// dear imgui, v1.91.0 WIP

// (main code and documentation)

// Help:

// - See links below.

// - Call and read ImGui::ShowDemoWindow() in imgui_demo.cpp. All applications in examples/ are doing that.

// - Read top of imgui.cpp for more details, links and comments.

// Resources:

// - FAQ ........................ https://dearimgui.com/faq (in repository as docs/FAQ.md)

// - Homepage ................... https://github.com/ocornut/imgui

// - Releases & changelog ....... https://github.com/ocornut/imgui/releases

// - Gallery .................... https://github.com/ocornut/imgui/issues/7503 (please post your screenshots/video there!)

// - Wiki ....................... https://github.com/ocornut/imgui/wiki (lots of good stuff there)

//   - Getting Started            https://github.com/ocornut/imgui/wiki/Getting-Started (how to integrate in an existing app by adding ~25 lines of code)

//   - Third-party Extensions     https://github.com/ocornut/imgui/wiki/Useful-Extensions (ImPlot & many more)

//   - Bindings/Backends          https://github.com/ocornut/imgui/wiki/Bindings (language bindings, backends for various tech/engines)

//   - Glossary                   https://github.com/ocornut/imgui/wiki/Glossary

//   - Debug Tools                https://github.com/ocornut/imgui/wiki/Debug-Tools

//   - Software using Dear ImGui  https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui

// - Issues & support ........... https://github.com/ocornut/imgui/issues

// - Test Engine & Automation ... https://github.com/ocornut/imgui_test_engine (test suite, test engine to automate your apps)

// For first-time users having issues compiling/linking/running/loading fonts:

// please post in https://github.com/ocornut/imgui/discussions if you cannot find a solution in resources above.

// Everything else should be asked in 'Issues'! We are building a database of cross-linked knowledge there.

// Copyright (c) 2014-2024 Omar Cornut

// Developed by Omar Cornut and every direct or indirect contributors to the GitHub.

// See LICENSE.txt for copyright and licensing details (standard MIT License).

// This library is free but needs your support to sustain development and maintenance.

// Businesses: you can support continued development via B2B invoiced technical support, maintenance and sponsoring contracts.

// PLEASE reach out at omar AT dearimgui DOT com. See https://github.com/ocornut/imgui/wiki/Funding

// Businesses: you can also purchase licenses for the Dear ImGui Automation/Test Engine.

// It is recommended that you don't modify imgui.cpp! It will become difficult for you to update the library.

// Note that 'ImGui::' being a namespace, you can add functions into the namespace from your own source files, without

// modifying imgui.h or imgui.cpp. You may include imgui_internal.h to access internal data structures, but it doesn't

// come with any guarantee of forward compatibility. Discussing your changes on the GitHub Issue Tracker may lead you

// to a better solution or official support for them.

/*

Index of this file:

DOCUMENTATION

- MISSION STATEMENT

- CONTROLS GUIDE

- PROGRAMMER GUIDE

  - READ FIRST

  - HOW TO UPDATE TO A NEWER VERSION OF DEAR IMGUI

  - GETTING STARTED WITH INTEGRATING DEAR IMGUI IN YOUR CODE/ENGINE

  - HOW A SIMPLE APPLICATION MAY LOOK LIKE

  - HOW A SIMPLE RENDERING FUNCTION MAY LOOK LIKE

- API BREAKING CHANGES (read me when you update!)

- FREQUENTLY ASKED QUESTIONS (FAQ)

  - Read all answers online: https://www.dearimgui.com/faq, or in docs/FAQ.md (with a Markdown viewer)

CODE

(search for "[SECTION]" in the code to find them)

// [SECTION] INCLUDES

// [SECTION] FORWARD DECLARATIONS

// [SECTION] CONTEXT AND MEMORY ALLOCATORS

// [SECTION] USER FACING STRUCTURES (ImGuiStyle, ImGuiIO)

// [SECTION] MISC HELPERS/UTILITIES (Geometry functions)

// [SECTION] MISC HELPERS/UTILITIES (String, Format, Hash functions)

// [SECTION] MISC HELPERS/UTILITIES (File functions)

// [SECTION] MISC HELPERS/UTILITIES (ImText* functions)

// [SECTION] MISC HELPERS/UTILITIES (Color functions)

// [SECTION] ImGuiStorage

// [SECTION] ImGuiTextFilter

// [SECTION] ImGuiTextBuffer, ImGuiTextIndex

// [SECTION] ImGuiListClipper

// [SECTION] STYLING

// [SECTION] RENDER HELPERS

// [SECTION] INITIALIZATION, SHUTDOWN

// [SECTION] MAIN CODE (most of the code! lots of stuff, needs tidying up!)

// [SECTION] ID STACK

// [SECTION] INPUTS

// [SECTION] ERROR CHECKING

// [SECTION] ITEM SUBMISSION

// [SECTION] LAYOUT

// [SECTION] SCROLLING

// [SECTION] TOOLTIPS

// [SECTION] POPUPS

// [SECTION] KEYBOARD/GAMEPAD NAVIGATION

// [SECTION] DRAG AND DROP

// [SECTION] LOGGING/CAPTURING

// [SECTION] SETTINGS

// [SECTION] LOCALIZATION

// [SECTION] VIEWPORTS, PLATFORM WINDOWS

// [SECTION] DOCKING

// [SECTION] PLATFORM DEPENDENT HELPERS

// [SECTION] METRICS/DEBUGGER WINDOW

// [SECTION] DEBUG LOG WINDOW

// [SECTION] OTHER DEBUG TOOLS (ITEM PICKER, ID STACK TOOL)

*/

//-----------------------------------------------------------------------------

// DOCUMENTATION

//-----------------------------------------------------------------------------

/*

 MISSION STATEMENT

 =================

 - Easy to use to create code-driven and data-driven tools.

 - Easy to use to create ad hoc short-lived tools and long-lived, more elaborate tools.

 - Easy to hack and improve.

 - Minimize setup and maintenance.

 - Minimize state storage on user side.

 - Minimize state synchronization.

 - Portable, minimize dependencies, run on target (consoles, phones, etc.).

 - Efficient runtime and memory consumption.

 Designed primarily for developers and content-creators, not the typical end-user!

 Some of the current weaknesses (which we aim to address in the future) includes:

 - Doesn't look fancy.

 - Limited layout features, intricate layouts are typically crafted in code.

 CONTROLS GUIDE

 ==============

 - MOUSE CONTROLS

   - Mouse wheel:                   Scroll vertically.

   - SHIFT+Mouse wheel:             Scroll horizontally.

   - Click [X]:                     Close a window, available when 'bool* p_open' is passed to ImGui::Begin().

   - Click ^, Double-Click title:   Collapse window.

   - Drag on corner/border:         Resize window (double-click to auto fit window to its contents).

   - Drag on any empty space:       Move window (unless io.ConfigWindowsMoveFromTitleBarOnly = true).

   - Left-click outside popup:      Close popup stack (right-click over underlying popup: Partially close popup stack).

 - TEXT EDITOR

   - Hold SHIFT or Drag Mouse:      Select text.

   - CTRL+Left/Right:               Word jump.

   - CTRL+Shift+Left/Right:         Select words.

   - CTRL+A or Double-Click:        Select All.

   - CTRL+X, CTRL+C, CTRL+V:        Use OS clipboard.

   - CTRL+Z, CTRL+Y:                Undo, Redo.

   - ESCAPE:                        Revert text to its original value.

   - On OSX, controls are automatically adjusted to match standard OSX text editing 2ts and behaviors.

 - KEYBOARD CONTROLS

   - Basic:

     - Tab, SHIFT+Tab               Cycle through text editable fields.

     - CTRL+Tab, CTRL+Shift+Tab     Cycle through windows.

     - CTRL+Click                   Input text into a Slider or Drag widget.

   - Extended features with `io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard`:

     - Tab, SHIFT+Tab:              Cycle through every items.

     - Arrow keys                   Move through items using directional navigation. Tweak value.

     - Arrow keys + Alt, Shift      Tweak slower, tweak faster (when using arrow keys).

     - Enter                        Activate item (prefer text input when possible).

     - Space                        Activate item (prefer tweaking with arrows when possible).

     - Escape                       Deactivate item, leave child window, close popup.

     - Page Up, Page Down           Previous page, next page.

     - Home, End                    Scroll to top, scroll to bottom.

     - Alt                          Toggle between scrolling layer and menu layer.

     - CTRL+Tab then Ctrl+Arrows    Move window. Hold SHIFT to resize instead of moving.

   - Output when ImGuiConfigFlags_NavEnableKeyboard set,

     - io.WantCaptureKeyboard flag is set when keyboard is claimed.

     - io.NavActive: true when a window is focused and it doesn't have the ImGuiWindowFlags_NoNavInputs flag set.

     - io.NavVisible: true when the navigation cursor is visible (usually goes to back false when mouse is used).

 - GAMEPAD CONTROLS

   - Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.

   - Particularly useful to use Dear ImGui on a console system (e.g. PlayStation, Switch, Xbox) without a mouse!

   - Download controller mapping PNG/PSD at http://dearimgui.com/controls_sheets

   - Backend support: backend needs to:

      - Set 'io.BackendFlags |= ImGuiBackendFlags_HasGamepad' + call io.AddKeyEvent/AddKeyAnalogEvent() with ImGuiKey_Gamepad_XXX keys.

      - For analog values (0.0f to 1.0f), backend is responsible to handling a dead-zone and rescaling inputs accordingly.

        Backend code will probably need to transform your raw inputs (such as e.g. remapping your 0.2..0.9 raw input range to 0.0..1.0 imgui range, etc.).

      - BEFORE 1.87, BACKENDS USED TO WRITE TO io.NavInputs[]. This is now obsolete. Please call io functions instead!

   - If you need to share inputs between your game and the Dear ImGui interface, the easiest approach is to go all-or-nothing,

     with a buttons combo to toggle the target. Please reach out if you think the game vs navigation input sharing could be improved.

 - REMOTE INPUTS SHARING & MOUSE EMULATION

   - PS4/PS5 users: Consider emulating a mouse cursor with DualShock touch pad or a spare analog stick as a mouse-emulation fallback.

   - Consoles/Tablet/Phone users: Consider using a Synergy 1.x server (on your PC) + run examples/libs/synergy/uSynergy.c (on your console/tablet/phone app)

     in order to share your PC mouse/keyboard.

   - See https://github.com/ocornut/imgui/wiki/Useful-Extensions#remoting for other remoting solutions.

   - On a TV/console system where readability may be lower or mouse inputs may be awkward, you may want to set the ImGuiConfigFlags_NavEnableSetMousePos flag.

     Enabling ImGuiConfigFlags_NavEnableSetMousePos + ImGuiBackendFlags_HasSetMousePos instructs Dear ImGui to move your mouse cursor along with navigation movements.

     When enabled, the NewFrame() function may alter 'io.MousePos' and set 'io.WantSetMousePos' to notify you that it wants the mouse cursor to be moved.

     When that happens your backend NEEDS to move the OS or underlying mouse cursor on the next frame. Some of the backends in examples/ do that.

     (If you set the NavEnableSetMousePos flag but don't honor 'io.WantSetMousePos' properly, Dear ImGui will misbehave as it will see your mouse moving back & forth!)

     (In a setup when you may not have easy control over the mouse cursor, e.g. uSynergy.c doesn't expose moving remote mouse cursor, you may want

     to set a boolean to ignore your other external mouse positions until the external source is moved again.)

 PROGRAMMER GUIDE

 ================

 READ FIRST

 ----------

 - Remember to check the wonderful Wiki (https://github.com/ocornut/imgui/wiki)

 - Your code creates the UI every frame of your application loop, if your code doesn't run the UI is gone!

   The UI can be highly dynamic, there are no construction or destruction steps, less superfluous

   data retention on your side, less state duplication, less state synchronization, fewer bugs.

 - Call and read ImGui::ShowDemoWindow() for demo code demonstrating most features.

   Or browse https://pthom.github.io/imgui_manual_online/manual/imgui_manual.html for interactive web version.

 - The library is designed to be built from sources. Avoid pre-compiled binaries and packaged versions. See imconfig.h to configure your build.

 - Dear ImGui is an implementation of the IMGUI paradigm (immediate-mode graphical user interface, a term coined by Casey Muratori).

   You can learn about IMGUI principles at http://www.johno.se/book/imgui.html, http://mollyrocket.com/861 & more links in Wiki.

 - Dear ImGui is a "single pass" rasterizing implementation of the IMGUI paradigm, aimed at ease of use and high-performances.

   For every application frame, your UI code will be called only once. This is in contrast to e.g. Unity's implementation of an IMGUI,

   where the UI code is called multiple times ("multiple passes") from a single entry point. There are pros and cons to both approaches.

 - Our origin is on the top-left. In axis aligned bounding boxes, Min = top-left, Max = bottom-right.

 - Please make sure you have asserts enabled (IM_ASSERT redirects to assert() by default, but can be redirected).

   If you get an assert, read the messages and comments around the assert.

 - This codebase aims to be highly optimized:

   - A typical idle frame should never call malloc/free.

   - We rely on a maximum of constant-time or O(N) algorithms. Limiting searches/scans as much as possible.

   - We put particular energy in making sure performances are decent with typical "Debug" build settings as well.

     Which mean we tend to avoid over-relying on "zero-cost abstraction" as they aren't zero-cost at all.

 - This codebase aims to be both highly opinionated and highly flexible:

   - This code works because of the things it choose to solve or not solve.

   - C++: this is a pragmatic C-ish codebase: we don't use fancy C++ features, we don't include C++ headers,

     and ImGui:: is a namespace. We rarely use member functions (and when we did, I am mostly regretting it now).

     This is to increase compatibility, increase maintainability and facilitate use from other languages.

   - C++: ImVec2/ImVec4 do not expose math operators by default, because it is expected that you use your own math types.

     See FAQ "How can I use my own math types instead of ImVec2/ImVec4?" for details about setting up imconfig.h for that.

     We can can optionally export math operators for ImVec2/ImVec4 using IMGUI_DEFINE_MATH_OPERATORS, which we use internally.

   - C++: pay attention that ImVector<> manipulates plain-old-data and does not honor construction/destruction

     (so don't use ImVector in your code or at our own risk!).

   - Building: We don't use nor mandate a build system for the main library.

     This is in an effort to ensure that it works in the real world aka with any esoteric build setup.

     This is also because providing a build system for the main library would be of little-value.

     The build problems are almost never coming from the main library but from specific backends.

 HOW TO UPDATE TO A NEWER VERSION OF DEAR IMGUI

 ----------------------------------------------

 - Update submodule or copy/overwrite every file.

 - About imconfig.h:

   - You may modify your copy of imconfig.h, in this case don't overwrite it.

   - or you may locally branch to modify imconfig.h and merge/rebase latest.

   - or you may '#define IMGUI_USER_CONFIG "my_config_file.h"' globally from your build system to

     specify a custom path for your imconfig.h file and instead not have to modify the default one.

 - Overwrite all the sources files except for imconfig.h (if you have modified your copy of imconfig.h)

 - Or maintain your own branch where you have imconfig.h modified as a top-most commit which you can regularly rebase over "master".

 - You can also use '#define IMGUI_USER_CONFIG "my_config_file.h" to redirect configuration to your own file.

 - Read the "API BREAKING CHANGES" section (below). This is where we list occasional API breaking changes.

   If a function/type has been renamed / or marked obsolete, try to fix the name in your code before it is permanently removed

   from the public API. If you have a problem with a missing function/symbols, search for its name in the code, there will

   likely be a comment about it. Please report any issue to the GitHub page!

 - To find out usage of old API, you can add '#define IMGUI_DISABLE_OBSOLETE_FUNCTIONS' in your configuration file.

 - Try to keep your copy of Dear ImGui reasonably up to date!

 GETTING STARTED WITH INTEGRATING DEAR IMGUI IN YOUR CODE/ENGINE

 ---------------------------------------------------------------

 - See https://github.com/ocornut/imgui/wiki/Getting-Started.

 - Run and study the examples and demo in imgui_demo.cpp to get acquainted with the library.

 - In the majority of cases you should be able to use unmodified backends files available in the backends/ folder.

 - Add the Dear ImGui source files + selected backend source files to your projects or using your preferred build system.

   It is recommended you build and statically link the .cpp files as part of your project and NOT as a shared library (DLL).

 - You can later customize the imconfig.h file to tweak some compile-time behavior, such as integrating Dear ImGui types with your own maths types.

 - When using Dear ImGui, your programming IDE is your friend: follow the declaration of variables, functions and types to find comments about them.

 - Dear ImGui never touches or knows about your GPU state. The only function that knows about GPU is the draw function that you provide.

   Effectively it means you can create widgets at any time in your code, regardless of considerations of being in "update" vs "render"

   phases of your own application. All rendering information is stored into command-lists that you will retrieve after calling ImGui::Render().

 - Refer to the backends and demo applications in the examples/ folder for instruction on how to setup your code.

 - If you are running over a standard OS with a common graphics API, you should be able to use unmodified imgui_impl_*** files from the examples/ folder.

 HOW A SIMPLE APPLICATION MAY LOOK LIKE

 --------------------------------------

 EXHIBIT 1: USING THE EXAMPLE BACKENDS (= imgui_impl_XXX.cpp files from the backends/ folder).

 The sub-folders in examples/ contain examples applications following this structure.

     // Application init: create a dear imgui context, setup some options, load fonts

     ImGui::CreateContext();

     ImGuiIO& io = ImGui::GetIO();

     // TODO: Set optional io.ConfigFlags values, e.g. 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard' to enable keyboard controls.

     // TODO: Fill optional fields of the io structure later.

     // TODO: Load TTF/OTF fonts if you don't want to use the default font.

     // Initialize helper Platform and Renderer backends (here we are using imgui_impl_win32.cpp and imgui_impl_dx11.cpp)

     ImGui_ImplWin32_Init(hwnd);

     ImGui_ImplDX11_Init(g_pd3dDevice, g_pd3dDeviceContext);

     // Application main loop

     while (true)

     {

         // Feed inputs to dear imgui, start new frame

         ImGui_ImplDX11_NewFrame();

         ImGui_ImplWin32_NewFrame();

         ImGui::NewFrame();

         // Any application code here

         ImGui::Text("Hello, world!");

         // Render dear imgui into screen

         ImGui::Render();

         ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());

         g_pSwapChain->Present(1, 0);

     }

     // Shutdown

     ImGui_ImplDX11_Shutdown();

     ImGui_ImplWin32_Shutdown();

     ImGui::DestroyContext();

 EXHIBIT 2: IMPLEMENTING CUSTOM BACKEND / CUSTOM ENGINE

     // Application init: create a dear imgui context, setup some options, load fonts

     ImGui::CreateContext();

     ImGuiIO& io = ImGui::GetIO();

     // TODO: Set optional io.ConfigFlags values, e.g. 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard' to enable keyboard controls.

     // TODO: Fill optional fields of the io structure later.

     // TODO: Load TTF/OTF fonts if you don't want to use the default font.

     // Build and load the texture atlas into a texture

     // (In the examples/ app this is usually done within the ImGui_ImplXXX_Init() function from one of the demo Renderer)

     int width, height;

     unsigned char* pixels = nullptr;

     io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);

     // At this point you've got the texture data and you need to upload that to your graphic system:

     // After we have created the texture, store its pointer/identifier (_in whichever format your engine uses_) in 'io.Fonts->TexID'.

     // This will be passed back to your via the renderer. Basically ImTextureID == void*. Read FAQ for details about ImTextureID.

     MyTexture* texture = MyEngine::CreateTextureFromMemoryPixels(pixels, width, height, TEXTURE_TYPE_RGBA32)

     io.Fonts->SetTexID((void*)texture);

     // Application main loop

     while (true)

     {

        // Setup low-level inputs, e.g. on Win32: calling GetKeyboardState(), or write to those fields from your Windows message handlers, etc.

        // (In the examples/ app this is usually done within the ImGui_ImplXXX_NewFrame() function from one of the demo Platform Backends)

        io.DeltaTime = 1.0f/60.0f;              // set the time elapsed since the previous frame (in seconds)

        io.DisplaySize.x = 1920.0f;             // set the current display width

        io.DisplaySize.y = 1280.0f;             // set the current display height here

        io.AddMousePosEvent(mouse_x, mouse_y);  // update mouse position

        io.AddMouseButtonEvent(0, mouse_b[0]);  // update mouse button states

        io.AddMouseButtonEvent(1, mouse_b[1]);  // update mouse button states

        // Call NewFrame(), after this point you can use ImGui::* functions anytime

        // (So you want to try calling NewFrame() as early as you can in your main loop to be able to use Dear ImGui everywhere)

        ImGui::NewFrame();

        // Most of your application code here

        ImGui::Text("Hello, world!");

        MyGameUpdate(); // may use any Dear ImGui functions, e.g. ImGui::Begin("My window"); ImGui::Text("Hello, world!"); ImGui::End();

        MyGameRender(); // may use any Dear ImGui functions as well!

        // Render dear imgui, swap buffers

        // (You want to try calling EndFrame/Render as late as you can, to be able to use Dear ImGui in your own game rendering code)

        ImGui::EndFrame();

        ImGui::Render();

        ImDrawData* draw_data = ImGui::GetDrawData();

        MyImGuiRenderFunction(draw_data);

        SwapBuffers();

     }

     // Shutdown

     ImGui::DestroyContext();

 To decide whether to dispatch mouse/keyboard inputs to Dear ImGui to the rest of your application,

 you should read the 'io.WantCaptureMouse', 'io.WantCaptureKeyboard' and 'io.WantTextInput' flags!

 Please read the FAQ entry "How can I tell whether to dispatch mouse/keyboard to Dear ImGui or my application?" about this.

 HOW A SIMPLE RENDERING FUNCTION MAY LOOK LIKE

 ---------------------------------------------

 The backends in impl_impl_XXX.cpp files contain many working implementations of a rendering function.

    void MyImGuiRenderFunction(ImDrawData* draw_data)

    {

       // TODO: Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled

       // TODO: Setup texture sampling state: sample with bilinear filtering (NOT point/nearest filtering). Use 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines;' to allow point/nearest filtering.

       // TODO: Setup viewport covering draw_data->DisplayPos to draw_data->DisplayPos + draw_data->DisplaySize

       // TODO: Setup orthographic projection matrix cover draw_data->DisplayPos to draw_data->DisplayPos + draw_data->DisplaySize

       // TODO: Setup shader: vertex { float2 pos, float2 uv, u32 color }, fragment shader sample color from 1 texture, multiply by vertex color.

       ImVec2 clip_off = draw_data->DisplayPos;

       for (int n = 0; n < draw_data->CmdListsCount; n++)

       {

          const ImDrawList* cmd_list = draw_data->CmdLists[n];

          const ImDrawVert* vtx_buffer = cmd_list->VtxBuffer.Data;  // vertex buffer generated by Dear ImGui

          const ImDrawIdx* idx_buffer = cmd_list->IdxBuffer.Data;   // index buffer generated by Dear ImGui

          for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)

          {

             const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];

             if (pcmd->UserCallback)

             {

                 pcmd->UserCallback(cmd_list, pcmd);

             }

             else

             {

                 // Project scissor/clipping rectangles into framebuffer space

                 ImVec2 clip_min(pcmd->ClipRect.x - clip_off.x, pcmd->ClipRect.y - clip_off.y);

                 ImVec2 clip_max(pcmd->ClipRect.z - clip_off.x, pcmd->ClipRect.w - clip_off.y);

                 if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)

                     continue;

                 // We are using scissoring to clip some objects. All low-level graphics API should support it.

                 // - If your engine doesn't support scissoring yet, you may ignore this at first. You will get some small glitches

                 //   (some elements visible outside their bounds) but you can fix that once everything else works!

                 // - Clipping coordinates are provided in imgui coordinates space:

                 //   - For a given viewport, draw_data->DisplayPos == viewport->Pos and draw_data->DisplaySize == viewport->Size

                 //   - In a single viewport application, draw_data->DisplayPos == (0,0) and draw_data->DisplaySize == io.DisplaySize, but always use GetMainViewport()->Pos/Size instead of hardcoding those values.

                 //   - In the interest of supporting multi-viewport applications (see 'docking' branch on github),

                 //     always subtract draw_data->DisplayPos from clipping bounds to convert them to your viewport space.

                 // - Note that pcmd->ClipRect contains Min+Max bounds. Some graphics API may use Min+Max, other may use Min+Size (size being Max-Min)

                 MyEngineSetScissor(clip_min.x, clip_min.y, clip_max.x, clip_max.y);

                 // The texture for the draw call is specified by pcmd->GetTexID().

                 // The vast majority of draw calls will use the Dear ImGui texture atlas, which value you have set yourself during initialization.

                 MyEngineBindTexture((MyTexture*)pcmd->GetTexID());

                 // Render 'pcmd->ElemCount/3' indexed triangles.

                 // By default the indices ImDrawIdx are 16-bit, you can change them to 32-bit in imconfig.h if your engine doesn't support 16-bit indices.

                 MyEngineDrawIndexedTriangles(pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer + pcmd->IdxOffset, vtx_buffer, pcmd->VtxOffset);

             }

          }

       }

    }

 API BREAKING CHANGES

 ====================

 Occasionally introducing changes that are breaking the API. We try to make the breakage minor and easy to fix.

 Below is a change-log of API breaking changes only. If you are using one of the functions listed, expect to have to fix some code.

 When you are not sure about an old symbol or function name, try using the Search/Find function of your IDE to look for comments or references in all imgui files.

 You can read releases logs https://github.com/ocornut/imgui/releases for more details.

(Docking/Viewport Branch)

 - 2024/XX/XX (1.XXXX) - when multi-viewports are enabled, all positions will be in your natural OS coordinates space. It means that:

                          - reference to hard-coded positions such as in SetNextWindowPos(ImVec2(0,0)) are probably not what you want anymore.

                            you may use GetMainViewport()->Pos to offset hard-coded positions, e.g. SetNextWindowPos(GetMainViewport()->Pos)

                          - likewise io.MousePos and GetMousePos() will use OS coordinates.

                            If you query mouse positions to interact with non-imgui coordinates you will need to offset them, e.g. subtract GetWindowViewport()->Pos.

 - 2024/07/15 (1.91.0) - renamed ImGuiSelectableFlags_DontClosePopups to ImGuiSelectableFlags_NoAutoClosePopups. (#1379, #1468, #2200, #4936, #5216, #7302, #7573)

                         (internals: also renamed ImGuiItemFlags_SelectableDontClosePopup into ImGuiItemFlags_AutoClosePopups with inverted behaviors)

 - 2024/07/15 (1.91.0) - obsoleted PushButtonRepeat()/PopButtonRepeat() in favor of using new PushItemFlag(ImGuiItemFlags_ButtonRepeat, ...)/PopItemFlag().

 - 2024/07/02 (1.91.0) - commented out obsolete ImGuiModFlags (renamed to ImGuiKeyChord in 1.89). (#4921, #456)

                       - commented out obsolete ImGuiModFlags_XXX values (renamed to ImGuiMod_XXX in 1.89). (#4921, #456)

                            - ImGuiModFlags_Ctrl -> ImGuiMod_Ctrl, ImGuiModFlags_Shift -> ImGuiMod_Shift etc.

 - 2024/07/02 (1.91.0) - IO, IME: renamed platform IME hook and added explicit context for consistency and future-proofness.

                            - old: io.SetPlatformImeDataFn(ImGuiViewport* viewport, ImGuiPlatformImeData* data);

                            - new: io.PlatformSetImeDataFn(ImGuiContext* ctx, ImGuiViewport* viewport, ImGuiPlatformImeData* data);

 - 2024/06/21 (1.90.9) - BeginChild: added ImGuiChildFlags_NavFlattened as a replacement for the window flag ImGuiWindowFlags_NavFlattened: the feature only ever made sense for BeginChild() anyhow.

                            - old: BeginChild("Name", size, 0, ImGuiWindowFlags_NavFlattened);

                            - new: BeginChild("Name", size, ImGuiChildFlags_NavFlattened, 0);

 - 2024/06/21 (1.90.9) - io: ClearInputKeys() (first exposed in 1.89.8) doesn't clear mouse data, newly added ClearInputMouse() does.

 - 2024/06/20 (1.90.9) - renamed ImGuiDragDropFlags_SourceAutoExpirePayload to ImGuiDragDropFlags_PayloadAutoExpire.

 - 2024/06/18 (1.90.9) - style: renamed ImGuiCol_TabActive -> ImGuiCol_TabSelected, ImGuiCol_TabUnfocused -> ImGuiCol_TabDimmed, ImGuiCol_TabUnfocusedActive -> ImGuiCol_TabDimmedSelected.

 - 2024/06/10 (1.90.9) - removed old nested structure: renaming ImGuiStorage::ImGuiStoragePair type to ImGuiStoragePair (simpler for many languages).

 - 2024/06/06 (1.90.8) - reordered ImGuiInputTextFlags values. This should not be breaking unless you are using generated headers that have values not matching the main library.

 - 2024/06/06 (1.90.8) - removed 'ImGuiButtonFlags_MouseButtonDefault_ = ImGuiButtonFlags_MouseButtonLeft', was mostly unused and misleading.

 - 2024/05/27 (1.90.7) - commented out obsolete symbols marked obsolete in 1.88 (May 2022):

                            - old: CaptureKeyboardFromApp(bool)

                            - new: SetNextFrameWantCaptureKeyboard(bool)

                            - old: CaptureMouseFromApp(bool)

                            - new: SetNextFrameWantCaptureMouse(bool)

 - 2024/05/22 (1.90.7) - inputs (internals): renamed ImGuiKeyOwner_None to ImGuiKeyOwner_NoOwner, to make use more explicit and reduce confusion with the default it is a non-zero value and cannot be the default value (never made public, but disclosing as I expect a few users caught on owner-aware inputs).

                       - inputs (internals): renamed ImGuiInputFlags_RouteGlobalLow -> ImGuiInputFlags_RouteGlobal, ImGuiInputFlags_RouteGlobal -> ImGuiInputFlags_RouteGlobalOverFocused, ImGuiInputFlags_RouteGlobalHigh -> ImGuiInputFlags_RouteGlobalHighest.

                       - inputs (internals): Shortcut(), SetShortcutRouting(): swapped last two parameters order in function signatures:

                            - old: Shortcut(ImGuiKeyChord key_chord, ImGuiID owner_id = 0, ImGuiInputFlags flags = 0);

                            - new: Shortcut(ImGuiKeyChord key_chord, ImGuiInputFlags flags = 0, ImGuiID owner_id = 0);

                       - inputs (internals): owner-aware versions of IsKeyPressed(), IsKeyChordPressed(), IsMouseClicked(): swapped last two parameters order in function signatures.

                            - old: IsKeyPressed(ImGuiKey key, ImGuiID owner_id, ImGuiInputFlags flags = 0);

                            - new: IsKeyPressed(ImGuiKey key, ImGuiInputFlags flags, ImGuiID owner_id = 0);

                            - old: IsMouseClicked(ImGuiMouseButton button, ImGuiID owner_id, ImGuiInputFlags flags = 0);

                            - new: IsMouseClicked(ImGuiMouseButton button, ImGuiInputFlags flags, ImGuiID owner_id = 0);

                         for various reasons those changes makes sense. They are being made because making some of those API public.

                         only past users of imgui_internal.h with the extra parameters will be affected. Added asserts for valid flags in various functions to detect _some_ misuses, BUT NOT ALL.

 - 2024/05/21 (1.90.7) - docking: changed signature of DockSpaceOverViewport() to add explicit dockspace id if desired. pass 0 to use old behavior. (#7611)

                           - old: DockSpaceOverViewport(const ImGuiViewport* viewport = NULL, ImGuiDockNodeFlags flags = 0, ...);

                           - new: DockSpaceOverViewport(ImGuiID dockspace_id = 0, const ImGuiViewport* viewport = NULL, ImGuiDockNodeFlags flags = 0, ...);

 - 2024/05/16 (1.90.7) - inputs: on macOS X, Cmd and Ctrl keys are now automatically swapped by io.AddKeyEvent() as this naturally align with how macOS X uses those keys.

                           - it shouldn't really affect you unless you had custom shortcut swapping in place for macOS X apps.

                           - removed ImGuiMod_Shortcut which was previously dynamically remapping to Ctrl or Cmd/Super. It is now unnecessary to specific cross-platform idiomatic shortcuts. (#2343, #4084, #5923, #456)

 - 2024/05/14 (1.90.7) - backends: SDL_Renderer2 and SDL_Renderer3 backend now take a SDL_Renderer* in their RenderDrawData() functions.

 - 2024/04/18 (1.90.6) - TreeNode: Fixed a layout inconsistency when using an empty/hidden label followed by a SameLine() call. (#7505, #282)

                           - old: TreeNode("##Hidden"); SameLine(); Text("Hello");     // <-- This was actually incorrect! BUT appeared to look ok with the default style where ItemSpacing.x == FramePadding.x * 2 (it didn't look aligned otherwise).

                           - new: TreeNode("##Hidden"); SameLine(0, 0); Text("Hello"); // <-- This is correct for all styles values.

                         with the fix, IF you were successfully using TreeNode("")+SameLine(); you will now have extra spacing between your TreeNode and the following item.

                         You'll need to change the SameLine() call to SameLine(0,0) to remove this extraneous spacing. This seemed like the more sensible fix that's not making things less consistent.

                         (Note: when using this idiom you are likely to also use ImGuiTreeNodeFlags_SpanAvailWidth).

 - 2024/03/18 (1.90.5) - merged the radius_x/radius_y parameters in ImDrawList::AddEllipse(), AddEllipseFilled() and PathEllipticalArcTo() into a single ImVec2 parameter. Exceptionally, because those functions were added in 1.90, we are not adding inline redirection functions. The transition is easy and should affect few users. (#2743, #7417)

 - 2024/03/08 (1.90.5) - inputs: more formally obsoleted GetKeyIndex() when IMGUI_DISABLE_OBSOLETE_FUNCTIONS is set. It has been unnecessary and a no-op since 1.87 (it returns the same value as passed when used with a 1.87+ backend using io.AddKeyEvent() function). (#4921)

                           - IsKeyPressed(GetKeyIndex(ImGuiKey_XXX)) -> use IsKeyPressed(ImGuiKey_XXX)

 - 2024/01/15 (1.90.2) - commented out obsolete ImGuiIO::ImeWindowHandle marked obsolete in 1.87, favor of writing to 'void* ImGuiViewport::PlatformHandleRaw'.

 - 2023/12/19 (1.90.1) - commented out obsolete ImGuiKey_KeyPadEnter redirection to ImGuiKey_KeypadEnter.

 - 2023/11/06 (1.90.1) - removed CalcListClipping() marked obsolete in 1.86. Prefer using ImGuiListClipper which can return non-contiguous ranges.

 - 2023/11/05 (1.90.1) - imgui_freetype: commented out ImGuiFreeType::BuildFontAtlas() obsoleted in 1.81. prefer using #define IMGUI_ENABLE_FREETYPE or see commented code for manual calls.

 - 2023/11/05 (1.90.1) - internals,columns: commented out legacy ImGuiColumnsFlags_XXX symbols redirecting to ImGuiOldColumnsFlags_XXX, obsoleted from imgui_internal.h in 1.80.

 - 2023/11/09 (1.90.0) - removed IM_OFFSETOF() macro in favor of using offsetof() available in C++11. Kept redirection define (will obsolete).

 - 2023/11/07 (1.90.0) - removed BeginChildFrame()/EndChildFrame() in favor of using BeginChild() with the ImGuiChildFlags_FrameStyle flag. kept inline redirection function (will obsolete).

                         those functions were merely PushStyle/PopStyle helpers, the removal isn't so much motivated by needing to add the feature in BeginChild(), but by the necessity to avoid BeginChildFrame() signature mismatching BeginChild() signature and features.

 - 2023/11/02 (1.90.0) - BeginChild: upgraded 'bool border = true' parameter to 'ImGuiChildFlags flags' type, added ImGuiChildFlags_Border equivalent. As with our prior "bool-to-flags" API updates, the ImGuiChildFlags_Border value is guaranteed to be == true forever to ensure a smoother transition, meaning all existing calls will still work.

                           - old: BeginChild("Name", size, true)

                           - new: BeginChild("Name", size, ImGuiChildFlags_Border)

                           - old: BeginChild("Name", size, false)

                           - new: BeginChild("Name", size) or BeginChild("Name", 0) or BeginChild("Name", size, ImGuiChildFlags_None)

 - 2023/11/02 (1.90.0) - BeginChild: added child-flag ImGuiChildFlags_AlwaysUseWindowPadding as a replacement for the window-flag ImGuiWindowFlags_AlwaysUseWindowPadding: the feature only ever made sense for BeginChild() anyhow.

                           - old: BeginChild("Name", size, 0, ImGuiWindowFlags_AlwaysUseWindowPadding);

                           - new: BeginChild("Name", size, ImGuiChildFlags_AlwaysUseWindowPadding, 0);

 - 2023/09/27 (1.90.0) - io: removed io.MetricsActiveAllocations introduced in 1.63. Same as 'g.DebugMemAllocCount - g.DebugMemFreeCount' (still displayed in Metrics, unlikely to be accessed by end-user).

 - 2023/09/26 (1.90.0) - debug tools: Renamed ShowStackToolWindow() ("Stack Tool") to ShowIDStackToolWindow() ("ID Stack Tool"), as earlier name was misleading. Kept inline redirection function. (#4631)

 - 2023/09/15 (1.90.0) - ListBox, Combo: changed signature of "name getter" callback in old one-liner ListBox()/Combo() apis. kept inline redirection function (will obsolete).

                           - old: bool Combo(const char* label, int* current_item, bool (*getter)(void* user_data, int idx, const char** out_text), ...)

                           - new: bool Combo(const char* label, int* current_item, const char* (*getter)(void* user_data, int idx), ...);

                           - old: bool ListBox(const char* label, int* current_item, bool (*getting)(void* user_data, int idx, const char** out_text), ...);

                           - new: bool ListBox(const char* label, int* current_item, const char* (*getter)(void* user_data, int idx), ...);

 - 2023/09/08 (1.90.0) - commented out obsolete redirecting functions:

                           - GetWindowContentRegionWidth()  -> use GetWindowContentRegionMax().x - GetWindowContentRegionMin().x. Consider that generally 'GetContentRegionAvail().x' is more useful.

                           - ImDrawCornerFlags_XXX          -> use ImDrawFlags_RoundCornersXXX flags. Read 1.82 Changelog for details + grep commented names in sources.

                       - commented out runtime support for hardcoded ~0 or 0x01..0x0F rounding flags values for AddRect()/AddRectFilled()/PathRect()/AddImageRounded() -> use ImDrawFlags_RoundCornersXXX flags. Read 1.82 Changelog for details

 - 2023/08/25 (1.89.9) - clipper: Renamed IncludeRangeByIndices() (also called ForceDisplayRangeByIndices() before 1.89.6) to IncludeItemsByIndex(). Kept inline redirection function. Sorry!

 - 2023/07/12 (1.89.8) - ImDrawData: CmdLists now owned, changed from ImDrawList** to ImVector<ImDrawList*>. Majority of users shouldn't be affected, but you cannot compare to NULL nor reassign manually anymore. Instead use AddDrawList(). (#6406, #4879, #1878)

 - 2023/06/28 (1.89.7) - overlapping items: obsoleted 'SetItemAllowOverlap()' (called after item) in favor of calling 'SetNextItemAllowOverlap()' (called before item). 'SetItemAllowOverlap()' didn't and couldn't work reliably since 1.89 (2022-11-15).

 - 2023/06/28 (1.89.7) - overlapping items: renamed 'ImGuiTreeNodeFlags_AllowItemOverlap' to 'ImGuiTreeNodeFlags_AllowOverlap', 'ImGuiSelectableFlags_AllowItemOverlap' to 'ImGuiSelectableFlags_AllowOverlap'. Kept redirecting enums (will obsolete).

 - 2023/06/28 (1.89.7) - overlapping items: IsItemHovered() now by default return false when querying an item using AllowOverlap mode which is being overlapped. Use ImGuiHoveredFlags_AllowWhenOverlappedByItem to revert to old behavior.

 - 2023/06/28 (1.89.7) - overlapping items: Selectable and TreeNode don't allow overlap when active so overlapping widgets won't appear as hovered. While this fixes a common small visual issue, it also means that calling IsItemHovered() after a non-reactive elements - e.g. Text() - overlapping an active one may fail if you don't use IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByActiveItem). (#6610)

 - 2023/06/20 (1.89.7) - moved io.HoverDelayShort/io.HoverDelayNormal to style.HoverDelayShort/style.HoverDelayNormal. As the fields were added in 1.89 and expected to be left unchanged by most users, or only tweaked once during app initialization, we are exceptionally accepting the breakage.

 - 2023/05/30 (1.89.6) - backends: renamed "imgui_impl_sdlrenderer.cpp" to "imgui_impl_sdlrenderer2.cpp" and "imgui_impl_sdlrenderer.h" to "imgui_impl_sdlrenderer2.h". This is in prevision for the future release of SDL3.

 - 2023/05/22 (1.89.6) - listbox: commented out obsolete/redirecting functions that were marked obsolete more than two years ago:

                           - ListBoxHeader()  -> use BeginListBox() (note how two variants of ListBoxHeader() existed. Check commented versions in imgui.h for reference)

                           - ListBoxFooter()  -> use EndListBox()

 - 2023/05/15 (1.89.6) - clipper: commented out obsolete redirection constructor 'ImGuiListClipper(int items_count, float items_height = -1.0f)' that was marked obsolete in 1.79. Use default constructor + clipper.Begin().

 - 2023/05/15 (1.89.6) - clipper: renamed ImGuiListClipper::ForceDisplayRangeByIndices() to ImGuiListClipper::IncludeRangeByIndices().

 - 2023/03/14 (1.89.4) - commented out redirecting enums/functions names that were marked obsolete two years ago:

                           - ImGuiSliderFlags_ClampOnInput        -> use ImGuiSliderFlags_AlwaysClamp

                           - ImGuiInputTextFlags_AlwaysInsertMode -> use ImGuiInputTextFlags_AlwaysOverwrite

                           - ImDrawList::AddBezierCurve()         -> use ImDrawList::AddBezierCubic()

                           - ImDrawList::PathBezierCurveTo()      -> use ImDrawList::PathBezierCubicCurveTo()

 - 2023/03/09 (1.89.4) - renamed PushAllowKeyboardFocus()/PopAllowKeyboardFocus() to PushTabStop()/PopTabStop(). Kept inline redirection functions (will obsolete).

 - 2023/03/09 (1.89.4) - tooltips: Added 'bool' return value to BeginTooltip() for API consistency. Please only submit contents and call EndTooltip() if BeginTooltip() returns true. In reality the function will _currently_ always return true, but further changes down the line may change this, best to clarify API sooner.

 - 2023/02/15 (1.89.4) - moved the optional "courtesy maths operators" implementation from imgui_internal.h in imgui.h.

                         Even though we encourage using your own maths types and operators by setting up IM_VEC2_CLASS_EXTRA,

                         it has been frequently requested by people to use our own. We had an opt-in define which was

                         previously fulfilled in imgui_internal.h. It is now fulfilled in imgui.h. (#6164)

                           - OK:     #define IMGUI_DEFINE_MATH_OPERATORS / #include "imgui.h" / #include "imgui_internal.h"

                           - Error:  #include "imgui.h" / #define IMGUI_DEFINE_MATH_OPERATORS / #include "imgui_internal.h"

 - 2023/02/07 (1.89.3) - backends: renamed "imgui_impl_sdl.cpp" to "imgui_impl_sdl2.cpp" and "imgui_impl_sdl.h" to "imgui_impl_sdl2.h". (#6146) This is in prevision for the future release of SDL3.

 - 2022/10/26 (1.89)   - commented out redirecting OpenPopupContextItem() which was briefly the name of OpenPopupOnItemClick() from 1.77 to 1.79.

 - 2022/10/12 (1.89)   - removed runtime patching of invalid "%f"/"%0.f" format strings for DragInt()/SliderInt(). This was obsoleted in 1.61 (May 2018). See 1.61 changelog for details.

 - 2022/09/26 (1.89)   - renamed and merged keyboard modifiers key enums and flags into a same set. Kept inline redirection enums (will obsolete).

                           - ImGuiKey_ModCtrl  and ImGuiModFlags_Ctrl  -> ImGuiMod_Ctrl

                           - ImGuiKey_ModShift and ImGuiModFlags_Shift -> ImGuiMod_Shift

                           - ImGuiKey_ModAlt   and ImGuiModFlags_Alt   -> ImGuiMod_Alt

                           - ImGuiKey_ModSuper and ImGuiModFlags_Super -> ImGuiMod_Super

                         the ImGuiKey_ModXXX were introduced in 1.87 and mostly used by backends.

                         the ImGuiModFlags_XXX have been exposed in imgui.h but not really used by any public api only by third-party extensions.

                         exceptionally commenting out the older ImGuiKeyModFlags_XXX names ahead of obsolescence schedule to reduce confusion and because they were not meant to be used anyway.

 - 2022/09/20 (1.89)   - ImGuiKey is now a typed enum, allowing ImGuiKey_XXX symbols to be named in debuggers.

                         this will require uses of legacy backend-dependent indices to be casted, e.g.

                            - with imgui_impl_glfw:  IsKeyPressed(GLFW_KEY_A) -> IsKeyPressed((ImGuiKey)GLFW_KEY_A);

                            - with imgui_impl_win32: IsKeyPressed('A')        -> IsKeyPressed((ImGuiKey)'A')

                            - etc. However if you are upgrading code you might well use the better, backend-agnostic IsKeyPressed(ImGuiKey_A) now!

 - 2022/09/12 (1.89) - removed the bizarre legacy default argument for 'TreePush(const void* ptr = NULL)', always pass a pointer value explicitly. NULL/nullptr is ok but require cast, e.g. TreePush((void*)nullptr);

 - 2022/09/05 (1.89) - commented out redirecting functions/enums names that were marked obsolete in 1.77 and 1.78 (June 2020):

                         - DragScalar(), DragScalarN(), DragFloat(), DragFloat2(), DragFloat3(), DragFloat4(): For old signatures ending with (..., const char* format, float power = 1.0f) -> use (..., format ImGuiSliderFlags_Logarithmic) if power != 1.0f.

                         - SliderScalar(), SliderScalarN(), SliderFloat(), SliderFloat2(), SliderFloat3(), SliderFloat4(): For old signatures ending with (..., const char* format, float power = 1.0f) -> use (..., format ImGuiSliderFlags_Logarithmic) if power != 1.0f.

                         - BeginPopupContextWindow(const char*, ImGuiMouseButton, bool) -> use BeginPopupContextWindow(const char*, ImGuiPopupFlags)

 - 2022/09/02 (1.89) - obsoleted using SetCursorPos()/SetCursorScreenPos() to extend parent window/cell boundaries.

                       this relates to when moving the cursor position beyond current boundaries WITHOUT submitting an item.

                         - previously this would make the window content size ~200x200:

                              Begin(...) + SetCursorScreenPos(GetCursorScreenPos() + ImVec2(200,200)) + End();

                         - instead, please submit an item:

                              Begin(...) + SetCursorScreenPos(GetCursorScreenPos() + ImVec2(200,200)) + Dummy(ImVec2(0,0)) + End();

                         - alternative:

                              Begin(...) + Dummy(ImVec2(200,200)) + End();

                         - content size is now only extended when submitting an item!

                         - with '#define IMGUI_DISABLE_OBSOLETE_FUNCTIONS' this will now be detected and assert.

                         - without '#define IMGUI_DISABLE_OBSOLETE_FUNCTIONS' this will silently be fixed until we obsolete it.

 - 2022/08/03 (1.89) - changed signature of ImageButton() function. Kept redirection function (will obsolete).

                        - added 'const char* str_id' parameter + removed 'int frame_padding = -1' parameter.

                        - old signature: bool ImageButton(ImTextureID tex_id, ImVec2 size, ImVec2 uv0 = ImVec2(0,0), ImVec2 uv1 = ImVec2(1,1), int frame_padding = -1, ImVec4 bg_col = ImVec4(0,0,0,0), ImVec4 tint_col = ImVec4(1,1,1,1));

                          - used the ImTextureID value to create an ID. This was inconsistent with other functions, led to ID conflicts, and caused problems with engines using transient ImTextureID values.

                          - had a FramePadding override which was inconsistent with other functions and made the already-long signature even longer.

                        - new signature: bool ImageButton(const char* str_id, ImTextureID tex_id, ImVec2 size, ImVec2 uv0 = ImVec2(0,0), ImVec2 uv1 = ImVec2(1,1), ImVec4 bg_col = ImVec4(0,0,0,0), ImVec4 tint_col = ImVec4(1,1,1,1));

                          - requires an explicit identifier. You may still use e.g. PushID() calls and then pass an empty identifier.

                          - always uses style.FramePadding for padding, to be consistent with other buttons. You may use PushStyleVar() to alter this.

 - 2022/07/08 (1.89) - inputs: removed io.NavInputs[] and ImGuiNavInput enum (following 1.87 changes).

                        - Official backends from 1.87+                  -> no issue.

                        - Official backends from 1.60 to 1.86           -> will build and convert gamepad inputs, unless IMGUI_DISABLE_OBSOLETE_KEYIO is defined. Need updating!

                        - Custom backends not writing to io.NavInputs[] -> no issue.

                        - Custom backends writing to io.NavInputs[]     -> will build and convert gamepad inputs, unless IMGUI_DISABLE_OBSOLETE_KEYIO is defined. Need fixing!

                        - TL;DR: Backends should call io.AddKeyEvent()/io.AddKeyAnalogEvent() with ImGuiKey_GamepadXXX values instead of filling io.NavInput[].

 - 2022/06/15 (1.88) - renamed IMGUI_DISABLE_METRICS_WINDOW to IMGUI_DISABLE_DEBUG_TOOLS for correctness. kept support for old define (will obsolete).

 - 2022/05/03 (1.88) - backends: osx: removed ImGui_ImplOSX_HandleEvent() from backend API in favor of backend automatically handling event capture. All ImGui_ImplOSX_HandleEvent() calls should be removed as they are now unnecessary.

 - 2022/04/05 (1.88) - inputs: renamed ImGuiKeyModFlags to ImGuiModFlags. Kept inline redirection enums (will obsolete). This was never used in public API functions but technically present in imgui.h and ImGuiIO.

 - 2022/01/20 (1.87) - inputs: reworded gamepad IO.

                        - Backend writing to io.NavInputs[]            -> backend should call io.AddKeyEvent()/io.AddKeyAnalogEvent() with ImGuiKey_GamepadXXX values.

 - 2022/01/19 (1.87) - sliders, drags: removed support for legacy arithmetic operators (+,+-,*,/) when inputing text. This doesn't break any api/code but a feature that used to be accessible by end-users (which seemingly no one used).

 - 2022/01/17 (1.87) - inputs: reworked mouse IO.

                        - Backend writing to io.MousePos               -> backend should call io.AddMousePosEvent()

                        - Backend writing to io.MouseDown[]            -> backend should call io.AddMouseButtonEvent()

                        - Backend writing to io.MouseWheel             -> backend should call io.AddMouseWheelEvent()

                        - Backend writing to io.MouseHoveredViewport   -> backend should call io.AddMouseViewportEvent() [Docking branch w/ multi-viewports only]

                       note: for all calls to IO new functions, the Dear ImGui context should be bound/current.

                       read https://github.com/ocornut/imgui/issues/4921 for details.

 - 2022/01/10 (1.87) - inputs: reworked keyboard IO. Removed io.KeyMap[], io.KeysDown[] in favor of calling io.AddKeyEvent(). Removed GetKeyIndex(), now unnecessary. All IsKeyXXX() functions now take ImGuiKey values. All features are still functional until IMGUI_DISABLE_OBSOLETE_KEYIO is defined. Read Changelog and Release Notes for details.

                        - IsKeyPressed(MY_NATIVE_KEY_XXX)              -> use IsKeyPressed(ImGuiKey_XXX)

                        - IsKeyPressed(GetKeyIndex(ImGuiKey_XXX))      -> use IsKeyPressed(ImGuiKey_XXX)

                        - Backend writing to io.KeyMap[],io.KeysDown[] -> backend should call io.AddKeyEvent() (+ call io.SetKeyEventNativeData() if you want legacy user code to stil function with legacy key codes).

                        - Backend writing to io.KeyCtrl, io.KeyShift.. -> backend should call io.AddKeyEvent() with ImGuiMod_XXX values. *IF YOU PULLED CODE BETWEEN 2021/01/10 and 2021/01/27: We used to have a io.AddKeyModsEvent() function which was now replaced by io.AddKeyEvent() with ImGuiMod_XXX values.*

                     - one case won't work with backward compatibility: if your custom backend used ImGuiKey as mock native indices (e.g. "io.KeyMap[ImGuiKey_A] = ImGuiKey_A") because those values are now larger than the legacy KeyDown[] array. Will assert.

                     - inputs: added ImGuiKey_ModCtrl/ImGuiKey_ModShift/ImGuiKey_ModAlt/ImGuiKey_ModSuper values to submit keyboard modifiers using io.AddKeyEvent(), instead of writing directly to io.KeyCtrl, io.KeyShift, io.KeyAlt, io.KeySuper.

 - 2022/01/05 (1.87) - inputs: renamed ImGuiKey_KeyPadEnter to ImGuiKey_KeypadEnter to align with new symbols. Kept redirection enum.

 - 2022/01/05 (1.87) - removed io.ImeSetInputScreenPosFn() in favor of more flexible io.SetPlatformImeDataFn(). Removed 'void* io.ImeWindowHandle' in favor of writing to 'void* ImGuiViewport::PlatformHandleRaw'.

 - 2022/01/01 (1.87) - commented out redirecting functions/enums names that were marked obsolete in 1.69, 1.70, 1.71, 1.72 (March-July 2019)

                        - ImGui::SetNextTreeNodeOpen()        -> use ImGui::SetNextItemOpen()

                        - ImGui::GetContentRegionAvailWidth() -> use ImGui::GetContentRegionAvail().x

                        - ImGui::TreeAdvanceToLabelPos()      -> use ImGui::SetCursorPosX(ImGui::GetCursorPosX() + ImGui::GetTreeNodeToLabelSpacing());

                        - ImFontAtlas::CustomRect             -> use ImFontAtlasCustomRect

                        - ImGuiColorEditFlags_RGB/HSV/HEX     -> use ImGuiColorEditFlags_DisplayRGB/HSV/Hex

 - 2021/12/20 (1.86) - backends: removed obsolete Marmalade backend (imgui_impl_marmalade.cpp) + example. Find last supported version at https://github.com/ocornut/imgui/wiki/Bindings

 - 2021/11/04 (1.86) - removed CalcListClipping() function. Prefer using ImGuiListClipper which can return non-contiguous ranges. Please open an issue if you think you really need this function.

 - 2021/08/23 (1.85) - removed GetWindowContentRegionWidth() function. keep inline redirection helper. can use 'GetWindowContentRegionMax().x - GetWindowContentRegionMin().x' instead for generally 'GetContentRegionAvail().x' is more useful.

 - 2021/07/26 (1.84) - commented out redirecting functions/enums names that were marked obsolete in 1.67 and 1.69 (March 2019):

                        - ImGui::GetOverlayDrawList() -> use ImGui::GetForegroundDrawList()

                        - ImFont::GlyphRangesBuilder  -> use ImFontGlyphRangesBuilder

 - 2021/05/19 (1.83) - backends: obsoleted direct access to ImDrawCmd::TextureId in favor of calling ImDrawCmd::GetTexID().

                        - if you are using official backends from the source tree: you have nothing to do.

                        - if you have copied old backend code or using your own: change access to draw_cmd->TextureId to draw_cmd->GetTexID().

 - 2021/03/12 (1.82) - upgraded ImDrawList::AddRect(), AddRectFilled(), PathRect() to use ImDrawFlags instead of ImDrawCornersFlags.

                        - ImDrawCornerFlags_TopLeft  -> use ImDrawFlags_RoundCornersTopLeft

                        - ImDrawCornerFlags_BotRight -> use ImDrawFlags_RoundCornersBottomRight

                        - ImDrawCornerFlags_None     -> use ImDrawFlags_RoundCornersNone etc.

                       flags now sanely defaults to 0 instead of 0x0F, consistent with all other flags in the API.

                       breaking: the default with rounding > 0.0f is now "round all corners" vs old implicit "round no corners":

                        - rounding == 0.0f + flags == 0 --> meant no rounding  --> unchanged (common use)

                        - rounding  > 0.0f + flags != 0 --> meant rounding     --> unchanged (common use)

                        - rounding == 0.0f + flags != 0 --> meant no rounding  --> unchanged (unlikely use)

                        - rounding  > 0.0f + flags == 0 --> meant no rounding  --> BREAKING (unlikely use): will now round all corners --> use ImDrawFlags_RoundCornersNone or rounding == 0.0f.

                       this ONLY matters for hard coded use of 0 + rounding > 0.0f. Use of named ImDrawFlags_RoundCornersNone (new) or ImDrawCornerFlags_None (old) are ok.

                       the old ImDrawCornersFlags used awkward default values of ~0 or 0xF (4 lower bits set) to signify "round all corners" and we sometimes encouraged using them as shortcuts.

                       legacy path still support use of hard coded ~0 or any value from 0x1 or 0xF. They will behave the same with legacy paths enabled (will assert otherwise).

 - 2021/03/11 (1.82) - removed redirecting functions/enums names that were marked obsolete in 1.66 (September 2018):

                        - ImGui::SetScrollHere()              -> use ImGui::SetScrollHereY()

 - 2021/03/11 (1.82) - clarified that ImDrawList::PathArcTo(), ImDrawList::PathArcToFast() won't render with radius < 0.0f. Previously it sorts of accidentally worked but would generally lead to counter-clockwise paths and have an effect on anti-aliasing.

 - 2021/03/10 (1.82) - upgraded ImDrawList::AddPolyline() and PathStroke() "bool closed" parameter to "ImDrawFlags flags". The matching ImDrawFlags_Closed value is guaranteed to always stay == 1 in the future.

 - 2021/02/22 (1.82) - (*undone in 1.84*) win32+mingw: Re-enabled IME functions by default even under MinGW. In July 2016, issue #738 had me incorrectly disable those default functions for MinGW. MinGW users should: either link with -limm32, either set their imconfig file  with '#define IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS'.

 - 2021/02/17 (1.82) - renamed rarely used style.CircleSegmentMaxError (old default = 1.60f) to style.CircleTessellationMaxError (new default = 0.30f) as the meaning of the value changed.

 - 2021/02/03 (1.81) - renamed ListBoxHeader(const char* label, ImVec2 size) to BeginListBox(). Kept inline redirection function (will obsolete).

                     - removed ListBoxHeader(const char* label, int items_count, int height_in_items = -1) in favor of specifying size. Kept inline redirection function (will obsolete).

                     - renamed ListBoxFooter() to EndListBox(). Kept inline redirection function (will obsolete).

 - 2021/01/26 (1.81) - removed ImGuiFreeType::BuildFontAtlas(). Kept inline redirection function. Prefer using '#define IMGUI_ENABLE_FREETYPE', but there's a runtime selection path available too. The shared extra flags parameters (very rarely used) are now stored in ImFontAtlas::FontBuilderFlags.

                     - renamed ImFontConfig::RasterizerFlags (used by FreeType) to ImFontConfig::FontBuilderFlags.

                     - renamed ImGuiFreeType::XXX flags to ImGuiFreeTypeBuilderFlags_XXX for consistency with other API.

 - 2020/10/12 (1.80) - removed redirecting functions/enums that were marked obsolete in 1.63 (August 2018):

                        - ImGui::IsItemDeactivatedAfterChange() -> use ImGui::IsItemDeactivatedAfterEdit().

                        - ImGuiCol_ModalWindowDarkening       -> use ImGuiCol_ModalWindowDimBg

                        - ImGuiInputTextCallback              -> use ImGuiTextEditCallback

                        - ImGuiInputTextCallbackData          -> use ImGuiTextEditCallbackData

 - 2020/12/21 (1.80) - renamed ImDrawList::AddBezierCurve() to AddBezierCubic(), and PathBezierCurveTo() to PathBezierCubicCurveTo(). Kept inline redirection function (will obsolete).

 - 2020/12/04 (1.80) - added imgui_tables.cpp file! Manually constructed project files will need the new file added!

 - 2020/11/18 (1.80) - renamed undocumented/internals ImGuiColumnsFlags_* to ImGuiOldColumnFlags_* in prevision of incoming Tables API.

 - 2020/11/03 (1.80) - renamed io.ConfigWindowsMemoryCompactTimer to io.ConfigMemoryCompactTimer as the feature will apply to other data structures

 - 2020/10/14 (1.80) - backends: moved all backends files (imgui_impl_XXXX.cpp, imgui_impl_XXXX.h) from examples/ to backends/.

 - 2020/10/12 (1.80) - removed redirecting functions/enums that were marked obsolete in 1.60 (April 2018):

                        - io.RenderDrawListsFn pointer        -> use ImGui::GetDrawData() value and call the render function of your backend

                        - ImGui::IsAnyWindowFocused()         -> use ImGui::IsWindowFocused(ImGuiFocusedFlags_AnyWindow)

                        - ImGui::IsAnyWindowHovered()         -> use ImGui::IsWindowHovered(ImGuiHoveredFlags_AnyWindow)

                        - ImGuiStyleVar_Count_                -> use ImGuiStyleVar_COUNT

                        - ImGuiMouseCursor_Count_             -> use ImGuiMouseCursor_COUNT

                      - removed redirecting functions names that were marked obsolete in 1.61 (May 2018):

                        - InputFloat (... int decimal_precision ...) -> use InputFloat (... const char* format ...) with format = "%.Xf" where X is your value for decimal_precision.

                        - same for InputFloat2()/InputFloat3()/InputFloat4() variants taking a `int decimal_precision` parameter.

 - 2020/10/05 (1.79) - removed ImGuiListClipper: Renamed constructor parameters which created an ambiguous alternative to using the ImGuiListClipper::Begin() function, with misleading edge cases (note: imgui_memory_editor <0.40 from imgui_club/ used this old clipper API. Update your copy if needed).

 - 2020/09/25 (1.79) - renamed ImGuiSliderFlags_ClampOnInput to ImGuiSliderFlags_AlwaysClamp. Kept redirection enum (will obsolete sooner because previous name was added recently).

 - 2020/09/25 (1.79) - renamed style.TabMinWidthForUnselectedCloseButton to style.TabMinWidthForCloseButton.

 - 2020/09/21 (1.79) - renamed OpenPopupContextItem() back to OpenPopupOnItemClick(), reverting the change from 1.77. For varieties of reason this is more self-explanatory.

 - 2020/09/21 (1.79) - removed return value from OpenPopupOnItemClick() - returned true on mouse release on an item - because it is inconsistent with other popup APIs and makes others misleading. It's also and unnecessary: you can use IsWindowAppearing() after BeginPopup() for a similar result.

 - 2020/09/17 (1.79) - removed ImFont::DisplayOffset in favor of ImFontConfig::GlyphOffset. DisplayOffset was applied after scaling and not very meaningful/useful outside of being needed by the default ProggyClean font. If you scaled this value after calling AddFontDefault(), this is now done automatically. It was also getting in the way of better font scaling, so let's get rid of it now!

 - 2020/08/17 (1.78) - obsoleted use of the trailing 'float power=1.0f' parameter for DragFloat(), DragFloat2(), DragFloat3(), DragFloat4(), DragFloatRange2(), DragScalar(), DragScalarN(), SliderFloat(), SliderFloat2(), SliderFloat3(), SliderFloat4(), SliderScalar(), SliderScalarN(), VSliderFloat() and VSliderScalar().

                       replaced the 'float power=1.0f' argument with integer-based flags defaulting to 0 (as with all our flags).

                       worked out a backward-compatibility scheme so hopefully most C++ codebase should not be affected. in short, when calling those functions:

                       - if you omitted the 'power' parameter (likely!), you are not affected.

                       - if you set the 'power' parameter to 1.0f (same as previous default value): 1/ your compiler may warn on float>int conversion, 2/ everything else will work. 3/ you can replace the 1.0f value with 0 to fix the warning, and be technically correct.

                       - if you set the 'power' parameter to >1.0f (to enable non-linear editing): 1/ your compiler may warn on float>int conversion, 2/ code will assert at runtime, 3/ in case asserts are disabled, the code will not crash and enable the _Logarithmic flag. 4/ you can replace the >1.0f value with ImGuiSliderFlags_Logarithmic to fix the warning/assert and get a _similar_ effect as previous uses of power >1.0f.

                       see https://github.com/ocornut/imgui/issues/3361 for all details.

                       kept inline redirection functions (will obsolete) apart for: DragFloatRange2(), VSliderFloat(), VSliderScalar(). For those three the 'float power=1.0f' version was removed directly as they were most unlikely ever used.

                       for shared code, you can version check at compile-time with `#if IMGUI_VERSION_NUM >= 17704`.

                     - obsoleted use of v_min > v_max in DragInt, DragFloat, DragScalar to lock edits (introduced in 1.73, was not demoed nor documented very), will be replaced by a more generic ReadOnly feature. You may use the ImGuiSliderFlags_ReadOnly internal flag in the meantime.

 - 2020/06/23 (1.77) - removed BeginPopupContextWindow(const char*, int mouse_button, bool also_over_items) in favor of BeginPopupContextWindow(const char*, ImGuiPopupFlags flags) with ImGuiPopupFlags_NoOverItems.

 - 2020/06/15 (1.77) - renamed OpenPopupOnItemClick() to OpenPopupContextItem(). Kept inline redirection function (will obsolete). [NOTE: THIS WAS REVERTED IN 1.79]

 - 2020/06/15 (1.77) - removed CalcItemRectClosestPoint() entry point which was made obsolete and asserting in December 2017.

 - 2020/04/23 (1.77) - removed unnecessary ID (first arg) of ImFontAtlas::AddCustomRectRegular().

 - 2020/01/22 (1.75) - ImDrawList::AddCircle()/AddCircleFilled() functions don't accept negative radius any more.

 - 2019/12/17 (1.75) - [undid this change in 1.76] made Columns() limited to 64 columns by asserting above that limit. While the current code technically supports it, future code may not so we're putting the restriction ahead.

 - 2019/12/13 (1.75) - [imgui_internal.h] changed ImRect() default constructor initializes all fields to 0.0f instead of (FLT_MAX,FLT_MAX,-FLT_MAX,-FLT_MAX). If you used ImRect::Add() to create bounding boxes by adding multiple points into it, you may need to fix your initial value.

 - 2019/12/08 (1.75) - removed redirecting functions/enums that were marked obsolete in 1.53 (December 2017):

                       - ShowTestWindow()                    -> use ShowDemoWindow()

                       - IsRootWindowFocused()               -> use IsWindowFocused(ImGuiFocusedFlags_RootWindow)

                       - IsRootWindowOrAnyChildFocused()     -> use IsWindowFocused(ImGuiFocusedFlags_RootAndChildWindows)

                       - SetNextWindowContentWidth(w)        -> use SetNextWindowContentSize(ImVec2(w, 0.0f)

                       - GetItemsLineHeightWithSpacing()     -> use GetFrameHeightWithSpacing()

                       - ImGuiCol_ChildWindowBg              -> use ImGuiCol_ChildBg

                       - ImGuiStyleVar_ChildWindowRounding   -> use ImGuiStyleVar_ChildRounding

                       - ImGuiTreeNodeFlags_AllowOverlapMode -> use ImGuiTreeNodeFlags_AllowItemOverlap

                       - IMGUI_DISABLE_TEST_WINDOWS          -> use IMGUI_DISABLE_DEMO_WINDOWS

 - 2019/12/08 (1.75) - obsoleted calling ImDrawList::PrimReserve() with a negative count (which was vaguely documented and rarely if ever used). Instead, we added an explicit PrimUnreserve() API.

 - 2019/12/06 (1.75) - removed implicit default parameter to IsMouseDragging(int button = 0) to be consistent with other mouse functions (none of the other functions have it).

 - 2019/11/21 (1.74) - ImFontAtlas::AddCustomRectRegular() now requires an ID larger than 0x110000 (instead of 0x10000) to conform with supporting Unicode planes 1-16 in a future update. ID below 0x110000 will now assert.

 - 2019/11/19 (1.74) - renamed IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS to IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS for consistency.

 - 2019/11/19 (1.74) - renamed IMGUI_DISABLE_MATH_FUNCTIONS to IMGUI_DISABLE_DEFAULT_MATH_FUNCTIONS for consistency.

 - 2019/10/22 (1.74) - removed redirecting functions/enums that were marked obsolete in 1.52 (October 2017):

                       - Begin() [old 5 args version]        -> use Begin() [3 args], use SetNextWindowSize() SetNextWindowBgAlpha() if needed

                       - IsRootWindowOrAnyChildHovered()     -> use IsWindowHovered(ImGuiHoveredFlags_RootAndChildWindows)

                       - AlignFirstTextHeightToWidgets()     -> use AlignTextToFramePadding()

                       - SetNextWindowPosCenter()            -> use SetNextWindowPos() with a pivot of (0.5f, 0.5f)

                       - ImFont::Glyph                       -> use ImFontGlyph

 - 2019/10/14 (1.74) - inputs: Fixed a miscalculation in the keyboard/mouse "typematic" repeat delay/rate calculation, used by keys and e.g. repeating mouse buttons as well as the GetKeyPressedAmount() function.

                       if you were using a non-default value for io.KeyRepeatRate (previous default was 0.250), you can add +io.KeyRepeatDelay to it to compensate for the fix.

                       The function was triggering on: 0.0 and (delay+rate*N) where (N>=1). Fixed formula responds to (N>=0). Effectively it made io.KeyRepeatRate behave like it was set to (io.KeyRepeatRate + io.KeyRepeatDelay).

                       If you never altered io.KeyRepeatRate nor used GetKeyPressedAmount() this won't affect you.

 - 2019/07/15 (1.72) - removed TreeAdvanceToLabelPos() which is rarely used and only does SetCursorPosX(GetCursorPosX() + GetTreeNodeToLabelSpacing()). Kept redirection function (will obsolete).

 - 2019/07/12 (1.72) - renamed ImFontAtlas::CustomRect to ImFontAtlasCustomRect. Kept redirection typedef (will obsolete).

 - 2019/06/14 (1.72) - removed redirecting functions/enums names that were marked obsolete in 1.51 (June 2017): ImGuiCol_Column*, ImGuiSetCond_*, IsItemHoveredRect(), IsPosHoveringAnyWindow(), IsMouseHoveringAnyWindow(), IsMouseHoveringWindow(), IMGUI_ONCE_UPON_A_FRAME. Grep this log for details and new names, or see how they were implemented until 1.71.

 - 2019/06/07 (1.71) - rendering of child window outer decorations (bg color, border, scrollbars) is now performed as part of the parent window. If you have

                       overlapping child windows in a same parent, and relied on their relative z-order to be mapped to their submission order, this will affect your rendering.

                       This optimization is disabled if the parent window has no visual output, because it appears to be the most common situation leading to the creation of overlapping child windows.

                       Please reach out if you are affected.

 - 2019/05/13 (1.71) - renamed SetNextTreeNodeOpen() to SetNextItemOpen(). Kept inline redirection function (will obsolete).

 - 2019/05/11 (1.71) - changed io.AddInputCharacter(unsigned short c) signature to io.AddInputCharacter(unsigned int c).

 - 2019/04/29 (1.70) - improved ImDrawList thick strokes (>1.0f) preserving correct thickness up to 90 degrees angles (e.g. rectangles). If you have custom rendering using thick lines, they will appear thicker now.

 - 2019/04/29 (1.70) - removed GetContentRegionAvailWidth(), use GetContentRegionAvail().x instead. Kept inline redirection function (will obsolete).

 - 2019/03/04 (1.69) - renamed GetOverlayDrawList() to GetForegroundDrawList(). Kept redirection function (will obsolete).

 - 2019/02/26 (1.69) - renamed ImGuiColorEditFlags_RGB/ImGuiColorEditFlags_HSV/ImGuiColorEditFlags_HEX to ImGuiColorEditFlags_DisplayRGB/ImGuiColorEditFlags_DisplayHSV/ImGuiColorEditFlags_DisplayHex. Kept redirection enums (will obsolete).

 - 2019/02/14 (1.68) - made it illegal/assert when io.DisplayTime == 0.0f (with an exception for the first frame). If for some reason your time step calculation gives you a zero value, replace it with an arbitrarily small value!

 - 2019/02/01 (1.68) - removed io.DisplayVisibleMin/DisplayVisibleMax (which were marked obsolete and removed from viewport/docking branch already).

 - 2019/01/06 (1.67) - renamed io.InputCharacters[], marked internal as was always intended. Please don't access directly, and use AddInputCharacter() instead!

 - 2019/01/06 (1.67) - renamed ImFontAtlas::GlyphRangesBuilder to ImFontGlyphRangesBuilder. Kept redirection typedef (will obsolete).

 - 2018/12/20 (1.67) - made it illegal to call Begin("") with an empty string. This somehow half-worked before but had various undesirable side-effects.

 - 2018/12/10 (1.67) - renamed io.ConfigResizeWindowsFromEdges to io.ConfigWindowsResizeFromEdges as we are doing a large pass on configuration flags.

 - 2018/10/12 (1.66) - renamed misc/stl/imgui_stl.* to misc/cpp/imgui_stdlib.* in prevision for other C++ helper files.

 - 2018/09/28 (1.66) - renamed SetScrollHere() to SetScrollHereY(). Kept redirection function (will obsolete).

 - 2018/09/06 (1.65) - renamed stb_truetype.h to imstb_truetype.h, stb_textedit.h to imstb_textedit.h, and stb_rect_pack.h to imstb_rectpack.h.

                       If you were conveniently using the imgui copy of those STB headers in your project you will have to update your include paths.

 - 2018/09/05 (1.65) - renamed io.OptCursorBlink/io.ConfigCursorBlink to io.ConfigInputTextCursorBlink. (#1427)

 - 2018/08/31 (1.64) - added imgui_widgets.cpp file, extracted and moved widgets code out of imgui.cpp into imgui_widgets.cpp. Re-ordered some of the code remaining in imgui.cpp.

                       NONE OF THE FUNCTIONS HAVE CHANGED. THE CODE IS SEMANTICALLY 100% IDENTICAL, BUT _EVERY_ FUNCTION HAS BEEN MOVED.

                       Because of this, any local modifications to imgui.cpp will likely conflict when you update. Read docs/CHANGELOG.txt for suggestions.

 - 2018/08/22 (1.63) - renamed IsItemDeactivatedAfterChange() to IsItemDeactivatedAfterEdit() for consistency with new IsItemEdited() API. Kept redirection function (will obsolete soonish as IsItemDeactivatedAfterChange() is very recent).

 - 2018/08/21 (1.63) - renamed ImGuiTextEditCallback to ImGuiInputTextCallback, ImGuiTextEditCallbackData to ImGuiInputTextCallbackData for consistency. Kept redirection types (will obsolete).

 - 2018/08/21 (1.63) - removed ImGuiInputTextCallbackData::ReadOnly since it is a duplication of (ImGuiInputTextCallbackData::Flags & ImGuiInputTextFlags_ReadOnly).

 - 2018/08/01 (1.63) - removed per-window ImGuiWindowFlags_ResizeFromAnySide beta flag in favor of a global io.ConfigResizeWindowsFromEdges [update 1.67 renamed to ConfigWindowsResizeFromEdges] to enable the feature.

 - 2018/08/01 (1.63) - renamed io.OptCursorBlink to io.ConfigCursorBlink [-> io.ConfigInputTextCursorBlink in 1.65], io.OptMacOSXBehaviors to ConfigMacOSXBehaviors for consistency.

 - 2018/07/22 (1.63) - changed ImGui::GetTime() return value from float to double to avoid accumulating floating point imprecisions over time.

 - 2018/07/08 (1.63) - style: renamed ImGuiCol_ModalWindowDarkening to ImGuiCol_ModalWindowDimBg for consistency with other features. Kept redirection enum (will obsolete).

 - 2018/06/08 (1.62) - examples: the imgui_impl_XXX files have been split to separate platform (Win32, GLFW, SDL2, etc.) from renderer (DX11, OpenGL, Vulkan,  etc.).

                       old backends will still work as is, however prefer using the separated backends as they will be updated to support multi-viewports.

                       when adopting new backends follow the main.cpp code of your preferred examples/ folder to know which functions to call.

                       in particular, note that old backends called ImGui::NewFrame() at the end of their ImGui_ImplXXXX_NewFrame() function.

 - 2018/06/06 (1.62) - renamed GetGlyphRangesChinese() to GetGlyphRangesChineseFull() to distinguish other variants and discourage using the full set.

 - 2018/06/06 (1.62) - TreeNodeEx()/TreeNodeBehavior(): the ImGuiTreeNodeFlags_CollapsingHeader helper now include the ImGuiTreeNodeFlags_NoTreePushOnOpen flag. See Changelog for details.

 - 2018/05/03 (1.61) - DragInt(): the default compile-time format string has been changed from "%.0f" to "%d", as we are not using integers internally any more.

                       If you used DragInt() with custom format strings, make sure you change them to use %d or an integer-compatible format.

                       To honor backward-compatibility, the DragInt() code will currently parse and modify format strings to replace %*f with %d, giving time to users to upgrade their code.

                       If you have IMGUI_DISABLE_OBSOLETE_FUNCTIONS enabled, the code will instead assert! You may run a reg-exp search on your codebase for e.g. "DragInt.*%f" to help you find them.

 - 2018/04/28 (1.61) - obsoleted InputFloat() functions taking an optional "int decimal_precision" in favor of an equivalent and more flexible "const char* format",

                       consistent with other functions. Kept redirection functions (will obsolete).

 - 2018/04/09 (1.61) - IM_DELETE() helper function added in 1.60 doesn't clear the input _pointer_ reference, more consistent with expectation and allows passing r-value.

 - 2018/03/20 (1.60) - renamed io.WantMoveMouse to io.WantSetMousePos for consistency and ease of understanding (was added in 1.52, _not_ used by core and only honored by some backend ahead of merging the Nav branch).

 - 2018/03/12 (1.60) - removed ImGuiCol_CloseButton, ImGuiCol_CloseButtonActive, ImGuiCol_CloseButtonHovered as the closing cross uses regular button colors now.

 - 2018/03/08 (1.60) - changed ImFont::DisplayOffset.y to default to 0 instead of +1. Fixed rounding of Ascent/Descent to match TrueType renderer. If you were adding or subtracting to ImFont::DisplayOffset check if your fonts are correctly aligned vertically.

 - 2018/03/03 (1.60) - renamed ImGuiStyleVar_Count_ to ImGuiStyleVar_COUNT and ImGuiMouseCursor_Count_ to ImGuiMouseCursor_COUNT for consistency with other public enums.

 - 2018/02/18 (1.60) - BeginDragDropSource(): temporarily removed the optional mouse_button=0 parameter because it is not really usable in many situations at the moment.

 - 2018/02/16 (1.60) - obsoleted the io.RenderDrawListsFn callback, you can call your graphics engine render function after ImGui::Render(). Use ImGui::GetDrawData() to retrieve the ImDrawData* to display.

 - 2018/02/07 (1.60) - reorganized context handling to be more explicit,

                       - YOU NOW NEED TO CALL ImGui::CreateContext() AT THE BEGINNING OF YOUR APP, AND CALL ImGui::DestroyContext() AT THE END.

                       - removed Shutdown() function, as DestroyContext() serve this purpose.

                       - you may pass a ImFontAtlas* pointer to CreateContext() to share a font atlas between contexts. Otherwise CreateContext() will create its own font atlas instance.

                       - removed allocator parameters from CreateContext(), they are now setup with SetAllocatorFunctions(), and shared by all contexts.

                       - removed the default global context and font atlas instance, which were confusing for users of DLL reloading and users of multiple contexts.

 - 2018/01/31 (1.60) - moved sample TTF files from extra_fonts/ to misc/fonts/. If you loaded files directly from the imgui repo you may need to update your paths.

 - 2018/01/11 (1.60) - obsoleted IsAnyWindowHovered() in favor of IsWindowHovered(ImGuiHoveredFlags_AnyWindow). Kept redirection function (will obsolete).

 - 2018/01/11 (1.60) - obsoleted IsAnyWindowFocused() in favor of IsWindowFocused(ImGuiFocusedFlags_AnyWindow). Kept redirection function (will obsolete).

 - 2018/01/03 (1.60) - renamed ImGuiSizeConstraintCallback to ImGuiSizeCallback, ImGuiSizeConstraintCallbackData to ImGuiSizeCallbackData.

 - 2017/12/29 (1.60) - removed CalcItemRectClosestPoint() which was weird and not really used by anyone except demo code. If you need it it's easy to replicate on your side.

 - 2017/12/24 (1.53) - renamed the emblematic ShowTestWindow() function to ShowDemoWindow(). Kept redirection function (will obsolete).

 - 2017/12/21 (1.53) - ImDrawList: renamed style.AntiAliasedShapes to style.AntiAliasedFill for consistency and as a way to explicitly break code that manipulate those flag at runtime. You can now manipulate ImDrawList::Flags

 - 2017/12/21 (1.53) - ImDrawList: removed 'bool anti_aliased = true' final parameter of ImDrawList::AddPolyline() and ImDrawList::AddConvexPolyFilled(). Prefer manipulating ImDrawList::Flags if you need to toggle them during the frame.

 - 2017/12/14 (1.53) - using the ImGuiWindowFlags_NoScrollWithMouse flag on a child window forwards the mouse wheel event to the parent window, unless either ImGuiWindowFlags_NoInputs or ImGuiWindowFlags_NoScrollbar are also set.

 - 2017/12/13 (1.53) - renamed GetItemsLineHeightWithSpacing() to GetFrameHeightWithSpacing(). Kept redirection function (will obsolete).

 - 2017/12/13 (1.53) - obsoleted IsRootWindowFocused() in favor of using IsWindowFocused(ImGuiFocusedFlags_RootWindow). Kept redirection function (will obsolete).

                     - obsoleted IsRootWindowOrAnyChildFocused() in favor of using IsWindowFocused(ImGuiFocusedFlags_RootAndChildWindows). Kept redirection function (will obsolete).

 - 2017/12/12 (1.53) - renamed ImGuiTreeNodeFlags_AllowOverlapMode to ImGuiTreeNodeFlags_AllowItemOverlap. Kept redirection enum (will obsolete).

 - 2017/12/10 (1.53) - removed SetNextWindowContentWidth(), prefer using SetNextWindowContentSize(). Kept redirection function (will obsolete).

 - 2017/11/27 (1.53) - renamed ImGuiTextBuffer::append() helper to appendf(), appendv() to appendfv(). If you copied the 'Log' demo in your code, it uses appendv() so that needs to be renamed.

 - 2017/11/18 (1.53) - Style, Begin: removed ImGuiWindowFlags_ShowBorders window flag. Borders are now fully set up in the ImGuiStyle structure (see e.g. style.FrameBorderSize, style.WindowBorderSize). Use ImGui::ShowStyleEditor() to look them up.

                       Please note that the style system will keep evolving (hopefully stabilizing in Q1 2018), and so custom styles will probably subtly break over time. It is recommended you use the StyleColorsClassic(), StyleColorsDark(), StyleColorsLight() functions.

 - 2017/11/18 (1.53) - Style: removed ImGuiCol_ComboBg in favor of combo boxes using ImGuiCol_PopupBg for consistency.

 - 2017/11/18 (1.53) - Style: renamed ImGuiCol_ChildWindowBg to ImGuiCol_ChildBg.

 - 2017/11/18 (1.53) - Style: renamed style.ChildWindowRounding to style.ChildRounding, ImGuiStyleVar_ChildWindowRounding to ImGuiStyleVar_ChildRounding.

 - 2017/11/02 (1.53) - obsoleted IsRootWindowOrAnyChildHovered() in favor of using IsWindowHovered(ImGuiHoveredFlags_RootAndChildWindows);

 - 2017/10/24 (1.52) - renamed IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCS/IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCS to IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS/IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS for consistency.

 - 2017/10/20 (1.52) - changed IsWindowHovered() default parameters behavior to return false if an item is active in another window (e.g. click-dragging item from another window to this window). You can use the newly introduced IsWindowHovered() flags to requests this specific behavior if you need it.

 - 2017/10/20 (1.52) - marked IsItemHoveredRect()/IsMouseHoveringWindow() as obsolete, in favor of using the newly introduced flags for IsItemHovered() and IsWindowHovered(). See https://github.com/ocornut/imgui/issues/1382 for details.

                       removed the IsItemRectHovered()/IsWindowRectHovered() names introduced in 1.51 since they were merely more consistent names for the two functions we are now obsoleting.

                         IsItemHoveredRect()        --> IsItemHovered(ImGuiHoveredFlags_RectOnly)

                         IsMouseHoveringAnyWindow() --> IsWindowHovered(ImGuiHoveredFlags_AnyWindow)

                         IsMouseHoveringWindow()    --> IsWindowHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup | ImGuiHoveredFlags_AllowWhenBlockedByActiveItem) [weird, old behavior]

 - 2017/10/17 (1.52) - marked the old 5-parameters version of Begin() as obsolete (still available). Use SetNextWindowSize()+Begin() instead!

 - 2017/10/11 (1.52) - renamed AlignFirstTextHeightToWidgets() to AlignTextToFramePadding(). Kept inline redirection function (will obsolete).

 - 2017/09/26 (1.52) - renamed ImFont::Glyph to ImFontGlyph. Kept redirection typedef (will obsolete).

 - 2017/09/25 (1.52) - removed SetNextWindowPosCenter() because SetNextWindowPos() now has the optional pivot information to do the same and more. Kept redirection function (will obsolete).

 - 2017/08/25 (1.52) - io.MousePos needs to be set to ImVec2(-FLT_MAX,-FLT_MAX) when mouse is unavailable/missing. Previously ImVec2(-1,-1) was enough but we now accept negative mouse coordinates. In your backend if you need to support unavailable mouse, make sure to replace "io.MousePos = ImVec2(-1,-1)" with "io.MousePos = ImVec2(-FLT_MAX,-FLT_MAX)".

 - 2017/08/22 (1.51) - renamed IsItemHoveredRect() to IsItemRectHovered(). Kept inline redirection function (will obsolete). -> (1.52) use IsItemHovered(ImGuiHoveredFlags_RectOnly)!

                     - renamed IsMouseHoveringAnyWindow() to IsAnyWindowHovered() for consistency. Kept inline redirection function (will obsolete).

                     - renamed IsMouseHoveringWindow() to IsWindowRectHovered() for consistency. Kept inline redirection function (will obsolete).

 - 2017/08/20 (1.51) - renamed GetStyleColName() to GetStyleColorName() for consistency.

 - 2017/08/20 (1.51) - added PushStyleColor(ImGuiCol idx, ImU32 col) overload, which _might_ cause an "ambiguous call" compilation error if you are using ImColor() with implicit cast. Cast to ImU32 or ImVec4 explicily to fix.

 - 2017/08/15 (1.51) - marked the weird IMGUI_ONCE_UPON_A_FRAME helper macro as obsolete. prefer using the more explicit ImGuiOnceUponAFrame type.

 - 2017/08/15 (1.51) - changed parameter order for BeginPopupContextWindow() from (const char*,int buttons,bool also_over_items) to (const char*,int buttons,bool also_over_items). Note that most calls relied on default parameters completely.

 - 2017/08/13 (1.51) - renamed ImGuiCol_Column to ImGuiCol_Separator, ImGuiCol_ColumnHovered to ImGuiCol_SeparatorHovered, ImGuiCol_ColumnActive to ImGuiCol_SeparatorActive. Kept redirection enums (will obsolete).

 - 2017/08/11 (1.51) - renamed ImGuiSetCond_Always to ImGuiCond_Always, ImGuiSetCond_Once to ImGuiCond_Once, ImGuiSetCond_FirstUseEver to ImGuiCond_FirstUseEver, ImGuiSetCond_Appearing to ImGuiCond_Appearing. Kept redirection enums (will obsolete).

 - 2017/08/09 (1.51) - removed ValueColor() helpers, they are equivalent to calling Text(label) + SameLine() + ColorButton().

 - 2017/08/08 (1.51) - removed ColorEditMode() and ImGuiColorEditMode in favor of ImGuiColorEditFlags and parameters to the various Color*() functions. The SetColorEditOptions() allows to initialize default but the user can still change them with right-click context menu.

                     - changed prototype of 'ColorEdit4(const char* label, float col[4], bool show_alpha = true)' to 'ColorEdit4(const char* label, float col[4], ImGuiColorEditFlags flags = 0)', where passing flags = 0x01 is a safe no-op (hello dodgy backward compatibility!). - check and run the demo window, under "Color/Picker Widgets", to understand the various new options.

                     - changed prototype of rarely used 'ColorButton(ImVec4 col, bool small_height = false, bool outline_border = true)' to 'ColorButton(const char* desc_id, ImVec4 col, ImGuiColorEditFlags flags = 0, ImVec2 size = ImVec2(0, 0))'

 - 2017/07/20 (1.51) - removed IsPosHoveringAnyWindow(ImVec2), which was partly broken and misleading. ASSERT + redirect user to io.WantCaptureMouse

 - 2017/05/26 (1.50) - removed ImFontConfig::MergeGlyphCenterV in favor of a more multipurpose ImFontConfig::GlyphOffset.

 - 2017/05/01 (1.50) - renamed ImDrawList::PathFill() (rarely used directly) to ImDrawList::PathFillConvex() for clarity.

 - 2016/11/06 (1.50) - BeginChild(const char*) now applies the stack id to the provided label, consistently with other functions as it should always have been. It shouldn't affect you unless (extremely unlikely) you were appending multiple times to a same child from different locations of the stack id. If that's the case, generate an id with GetID() and use it instead of passing string to BeginChild().

 - 2016/10/15 (1.50) - avoid 'void* user_data' parameter to io.SetClipboardTextFn/io.GetClipboardTextFn pointers. We pass io.ClipboardUserData to it.

 - 2016/09/25 (1.50) - style.WindowTitleAlign is now a ImVec2 (ImGuiAlign enum was removed). set to (0.5f,0.5f) for horizontal+vertical centering, (0.0f,0.0f) for upper-left, etc.

 - 2016/07/30 (1.50) - SameLine(x) with x>0.0f is now relative to left of column/group if any, and not always to left of window. This was sort of always the intent and hopefully, breakage should be minimal.

 - 2016/05/12 (1.49) - title bar (using ImGuiCol_TitleBg/ImGuiCol_TitleBgActive colors) isn't rendered over a window background (ImGuiCol_WindowBg color) anymore.

                       If your TitleBg/TitleBgActive alpha was 1.0f or you are using the default theme it will not affect you, otherwise if <1.0f you need to tweak your custom theme to readjust for the fact that we don't draw a WindowBg background behind the title bar.

                       This helper function will convert an old TitleBg/TitleBgActive color into a new one with the same visual output, given the OLD color and the OLD WindowBg color:

                       ImVec4 ConvertTitleBgCol(const ImVec4& win_bg_col, const ImVec4& title_bg_col) { float new_a = 1.0f - ((1.0f - win_bg_col.w) * (1.0f - title_bg_col.w)), k = title_bg_col.w / new_a; return ImVec4((win_bg_col.x * win_bg_col.w + title_bg_col.x) * k, (win_bg_col.y * win_bg_col.w + title_bg_col.y) * k, (win_bg_col.z * win_bg_col.w + title_bg_col.z) * k, new_a); }

                       If this is confusing, pick the RGB value from title bar from an old screenshot and apply this as TitleBg/TitleBgActive. Or you may just create TitleBgActive from a tweaked TitleBg color.

 - 2016/05/07 (1.49) - removed confusing set of GetInternalState(), GetInternalStateSize(), SetInternalState() functions. Now using CreateContext(), DestroyContext(), GetCurrentContext(), SetCurrentContext().

 - 2016/05/02 (1.49) - renamed SetNextTreeNodeOpened() to SetNextTreeNodeOpen(), no redirection.

 - 2016/05/01 (1.49) - obsoleted old signature of CollapsingHeader(const char* label, const char* str_id = NULL, bool display_frame = true, bool default_open = false) as extra parameters were badly designed and rarely used. You can replace the "default_open = true" flag in new API with CollapsingHeader(label, ImGuiTreeNodeFlags_DefaultOpen).

 - 2016/04/26 (1.49) - changed ImDrawList::PushClipRect(ImVec4 rect) to ImDrawList::PushClipRect(Imvec2 min,ImVec2 max,bool intersect_with_current_clip_rect=false). Note that higher-level ImGui::PushClipRect() is preferable because it will clip at logic/widget level, whereas ImDrawList::PushClipRect() only affect your renderer.

 - 2016/04/03 (1.48) - removed style.WindowFillAlphaDefault setting which was redundant. Bake default BG alpha inside style.Colors[ImGuiCol_WindowBg] and all other Bg color values. (ref GitHub issue #337).

 - 2016/04/03 (1.48) - renamed ImGuiCol_TooltipBg to ImGuiCol_PopupBg, used by popups/menus and tooltips. popups/menus were previously using ImGuiCol_WindowBg. (ref github issue #337)

 - 2016/03/21 (1.48) - renamed GetWindowFont() to GetFont(), GetWindowFontSize() to GetFontSize(). Kept inline redirection function (will obsolete).

 - 2016/03/02 (1.48) - InputText() completion/history/always callbacks: if you modify the text buffer manually (without using DeleteChars()/InsertChars() helper) you need to maintain the BufTextLen field. added an assert.

 - 2016/01/23 (1.48) - fixed not honoring exact width passed to PushItemWidth(), previously it would add extra FramePadding.x*2 over that width. if you had manual pixel-perfect alignment in place it might affect you.

 - 2015/12/27 (1.48) - fixed ImDrawList::AddRect() which used to render a rectangle 1 px too large on each axis.

 - 2015/12/04 (1.47) - renamed Color() helpers to ValueColor() - dangerously named, rarely used and probably to be made obsolete.

 - 2015/08/29 (1.45) - with the addition of horizontal scrollbar we made various fixes to inconsistencies with dealing with cursor position.

                       GetCursorPos()/SetCursorPos() functions now include the scrolled amount. It shouldn't affect the majority of users, but take note that SetCursorPosX(100.0f) puts you at +100 from the starting x position which may include scrolling, not at +100 from the window left side.

                       GetContentRegionMax()/GetWindowContentRegionMin()/GetWindowContentRegionMax() functions allow include the scrolled amount. Typically those were used in cases where no scrolling would happen so it may not be a problem, but watch out!

 - 2015/08/29 (1.45) - renamed style.ScrollbarWidth to style.ScrollbarSize

 - 2015/08/05 (1.44) - split imgui.cpp into extra files: imgui_demo.cpp imgui_draw.cpp imgui_internal.h that you need to add to your project.

 - 2015/07/18 (1.44) - fixed angles in ImDrawList::PathArcTo(), PathArcToFast() (introduced in 1.43) being off by an extra PI for no justifiable reason

 - 2015/07/14 (1.43) - add new ImFontAtlas::AddFont() API. For the old AddFont***, moved the 'font_no' parameter of ImFontAtlas::AddFont** functions to the ImFontConfig structure.

                       you need to render your textured triangles with bilinear filtering to benefit from sub-pixel positioning of text.

 - 2015/07/08 (1.43) - switched rendering data to use indexed rendering. this is saving a fair amount of CPU/GPU and enables us to get anti-aliasing for a marginal cost.

                       this necessary change will break your rendering function! the fix should be very easy. sorry for that :(

                     - if you are using a vanilla copy of one of the imgui_impl_XXX.cpp provided in the example, you just need to update your copy and you can ignore the rest.

                     - the signature of the io.RenderDrawListsFn handler has changed!

                       old: ImGui_XXXX_RenderDrawLists(ImDrawList** const cmd_lists, int cmd_lists_count)

                       new: ImGui_XXXX_RenderDrawLists(ImDrawData* draw_data).

                         parameters: 'cmd_lists' becomes 'draw_data->CmdLists', 'cmd_lists_count' becomes 'draw_data->CmdListsCount'

                         ImDrawList: 'commands' becomes 'CmdBuffer', 'vtx_buffer' becomes 'VtxBuffer', 'IdxBuffer' is new.

                         ImDrawCmd:  'vtx_count' becomes 'ElemCount', 'clip_rect' becomes 'ClipRect', 'user_callback' becomes 'UserCallback', 'texture_id' becomes 'TextureId'.

                     - each ImDrawList now contains both a vertex buffer and an index buffer. For each command, render ElemCount/3 triangles using indices from the index buffer.

                     - if you REALLY cannot render indexed primitives, you can call the draw_data->DeIndexAllBuffers() method to de-index the buffers. This is slow and a waste of CPU/GPU. Prefer using indexed rendering!

                     - refer to code in the examples/ folder or ask on the GitHub if you are unsure of how to upgrade. please upgrade!

 - 2015/07/10 (1.43) - changed SameLine() parameters from int to float.

 - 2015/07/02 (1.42) - renamed SetScrollPosHere() to SetScrollFromCursorPos(). Kept inline redirection function (will obsolete).

 - 2015/07/02 (1.42) - renamed GetScrollPosY() to GetScrollY(). Necessary to reduce confusion along with other scrolling functions, because positions (e.g. cursor position) are not equivalent to scrolling amount.

 - 2015/06/14 (1.41) - changed ImageButton() default bg_col parameter from (0,0,0,1) (black) to (0,0,0,0) (transparent) - makes a difference when texture have transparence

 - 2015/06/14 (1.41) - changed Selectable() API from (label, selected, size) to (label, selected, flags, size). Size override should have been rarely used. Sorry!

 - 2015/05/31 (1.40) - renamed GetWindowCollapsed() to IsWindowCollapsed() for consistency. Kept inline redirection function (will obsolete).

 - 2015/05/31 (1.40) - renamed IsRectClipped() to IsRectVisible() for consistency. Note that return value is opposite! Kept inline redirection function (will obsolete).

 - 2015/05/27 (1.40) - removed the third 'repeat_if_held' parameter from Button() - sorry! it was rarely used and inconsistent. Use PushButtonRepeat(true) / PopButtonRepeat() to enable repeat on desired buttons.

 - 2015/05/11 (1.40) - changed BeginPopup() API, takes a string identifier instead of a bool. ImGui needs to manage the open/closed state of popups. Call OpenPopup() to actually set the "open" state of a popup. BeginPopup() returns true if the popup is opened.

 - 2015/05/03 (1.40) - removed style.AutoFitPadding, using style.WindowPadding makes more sense (the default values were already the same).

 - 2015/04/13 (1.38) - renamed IsClipped() to IsRectClipped(). Kept inline redirection function until 1.50.

 - 2015/04/09 (1.38) - renamed ImDrawList::AddArc() to ImDrawList::AddArcFast() for compatibility with future API

 - 2015/04/03 (1.38) - removed ImGuiCol_CheckHovered, ImGuiCol_CheckActive, replaced with the more general ImGuiCol_FrameBgHovered, ImGuiCol_FrameBgActive.

 - 2014/04/03 (1.38) - removed support for passing -FLT_MAX..+FLT_MAX as the range for a SliderFloat(). Use DragFloat() or Inputfloat() instead.

 - 2015/03/17 (1.36) - renamed GetItemBoxMin()/GetItemBoxMax()/IsMouseHoveringBox() to GetItemRectMin()/GetItemRectMax()/IsMouseHoveringRect(). Kept inline redirection function until 1.50.

 - 2015/03/15 (1.36) - renamed style.TreeNodeSpacing to style.IndentSpacing, ImGuiStyleVar_TreeNodeSpacing to ImGuiStyleVar_IndentSpacing

 - 2015/03/13 (1.36) - renamed GetWindowIsFocused() to IsWindowFocused(). Kept inline redirection function until 1.50.

 - 2015/03/08 (1.35) - renamed style.ScrollBarWidth to style.ScrollbarWidth (casing)

 - 2015/02/27 (1.34) - renamed OpenNextNode(bool) to SetNextTreeNodeOpened(bool, ImGuiSetCond). Kept inline redirection function until 1.50.

 - 2015/02/27 (1.34) - renamed ImGuiSetCondition_*** to ImGuiSetCond_***, and _FirstUseThisSession becomes _Once.

 - 2015/02/11 (1.32) - changed text input callback ImGuiTextEditCallback return type from void-->int. reserved for future use, return 0 for now.

 - 2015/02/10 (1.32) - renamed GetItemWidth() to CalcItemWidth() to clarify its evolving behavior

 - 2015/02/08 (1.31) - renamed GetTextLineSpacing() to GetTextLineHeightWithSpacing()

 - 2015/02/01 (1.31) - removed IO.MemReallocFn (unused)

 - 2015/01/19 (1.30) - renamed ImGuiStorage::GetIntPtr()/GetFloatPtr() to GetIntRef()/GetIntRef() because Ptr was conflicting with actual pointer storage functions.

 - 2015/01/11 (1.30) - big font/image API change! now loads TTF file. allow for multiple fonts. no need for a PNG loader.

 - 2015/01/11 (1.30) - removed GetDefaultFontData(). uses io.Fonts->GetTextureData*() API to retrieve uncompressed pixels.

                       - old:  const void* png_data; unsigned int png_size; ImGui::GetDefaultFontData(NULL, NULL, &png_data, &png_size); [..Upload texture to GPU..];

                       - new:  unsigned char* pixels; int width, height; io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); [..Upload texture to GPU..]; io.Fonts->SetTexID(YourTexIdentifier);

                       you now have more flexibility to load multiple TTF fonts and manage the texture buffer for internal needs. It is now recommended that you sample the font texture with bilinear interpolation.

 - 2015/01/11 (1.30) - added texture identifier in ImDrawCmd passed to your render function (we can now render images). make sure to call io.Fonts->SetTexID()

 - 2015/01/11 (1.30) - removed IO.PixelCenterOffset (unnecessary, can be handled in user projection matrix)

 - 2015/01/11 (1.30) - removed ImGui::IsItemFocused() in favor of ImGui::IsItemActive() which handles all widgets

 - 2014/12/10 (1.18) - removed SetNewWindowDefaultPos() in favor of new generic API SetNextWindowPos(pos, ImGuiSetCondition_FirstUseEver)

 - 2014/11/28 (1.17) - moved IO.Font*** options to inside the IO.Font-> structure (FontYOffset, FontTexUvForWhite, FontBaseScale, FontFallbackGlyph)

 - 2014/11/26 (1.17) - reworked syntax of IMGUI_ONCE_UPON_A_FRAME helper macro to increase compiler compatibility

 - 2014/11/07 (1.15) - renamed IsHovered() to IsItemHovered()

 - 2014/10/02 (1.14) - renamed IMGUI_INCLUDE_IMGUI_USER_CPP to IMGUI_INCLUDE_IMGUI_USER_INL and imgui_user.cpp to imgui_user.inl (more IDE friendly)

 - 2014/09/25 (1.13) - removed 'text_end' parameter from IO.SetClipboardTextFn (the string is now always zero-terminated for simplicity)

 - 2014/09/24 (1.12) - renamed SetFontScale() to SetWindowFontScale()

 - 2014/09/24 (1.12) - moved IM_MALLOC/IM_REALLOC/IM_FREE preprocessor defines to IO.MemAllocFn/IO.MemReallocFn/IO.MemFreeFn

 - 2014/08/30 (1.09) - removed IO.FontHeight (now computed automatically)

 - 2014/08/30 (1.09) - moved IMGUI_FONT_TEX_UV_FOR_WHITE preprocessor define to IO.FontTexUvForWhite

 - 2014/08/28 (1.09) - changed the behavior of IO.PixelCenterOffset following various rendering fixes

 FREQUENTLY ASKED QUESTIONS (FAQ)

 ================================

 Read all answers online:

   https://www.dearimgui.com/faq or https://github.com/ocornut/imgui/blob/master/docs/FAQ.md (same url)

 Read all answers locally (with a text editor or ideally a Markdown viewer):

   docs/FAQ.md

 Some answers are copied down here to facilitate searching in code.

 Q&A: Basics

 ===========

 Q: Where is the documentation?

 A: This library is poorly documented at the moment and expects the user to be acquainted with C/C++.

    - Run the examples/ applications and explore them.

    - Read Getting Started (https://github.com/ocornut/imgui/wiki/Getting-Started) guide.

    - See demo code in imgui_demo.cpp and particularly the ImGui::ShowDemoWindow() function.

    - The demo covers most features of Dear ImGui, so you can read the code and see its output.

    - See documentation and comments at the top of imgui.cpp + effectively imgui.h.

    - 20+ standalone example applications using e.g. OpenGL/DirectX are provided in the

      examples/ folder to explain how to integrate Dear ImGui with your own engine/application.

    - The Wiki (https://github.com/ocornut/imgui/wiki) has many resources and links.

    - The Glossary (https://github.com/ocornut/imgui/wiki/Glossary) page also may be useful.

    - Your programming IDE is your friend, find the type or function declaration to find comments

      associated with it.

 Q: What is this library called?

 Q: Which version should I get?

 >> This library is called "Dear ImGui", please don't call it "ImGui" :)

 >> See https://www.dearimgui.com/faq for details.

 Q&A: Integration

 ================

 Q: How to get started?

 A: Read https://github.com/ocornut/imgui/wiki/Getting-Started. Read 'PROGRAMMER GUIDE' above. Read examples/README.txt.

 Q: How can I tell whether to dispatch mouse/keyboard to Dear ImGui or my application?

 A: You should read the 'io.WantCaptureMouse', 'io.WantCaptureKeyboard' and 'io.WantTextInput' flags!

 >> See https://www.dearimgui.com/faq for a fully detailed answer. You really want to read this.

 Q. How can I enable keyboard or gamepad controls?

 Q: How can I use this on a machine without mouse, keyboard or screen? (input share, remote display)

 Q: I integrated Dear ImGui in my engine and little squares are showing instead of text...

 Q: I integrated Dear ImGui in my engine and some elements are clipping or disappearing when I move windows around...

 Q: I integrated Dear ImGui in my engine and some elements are displaying outside their expected windows boundaries...

 >> See https://www.dearimgui.com/faq

 Q&A: Usage

 ----------

 Q: About the ID Stack system..

   - Why is my widget not reacting when I click on it?

   - How can I have widgets with an empty label?

   - How can I have multiple widgets with the same label?

   - How can I have multiple windows with the same label?

 Q: How can I display an image? What is ImTextureID, how does it work?

 Q: How can I use my own math types instead of ImVec2?

 Q: How can I interact with standard C++ types (such as std::string and std::vector)?

 Q: How can I display custom shapes? (using low-level ImDrawList API)

 >> See https://www.dearimgui.com/faq

 Q&A: Fonts, Text

 ================

 Q: How should I handle DPI in my application?

 Q: How can I load a different font than the default?

 Q: How can I easily use icons in my application?

 Q: How can I load multiple fonts?

 Q: How can I display and input non-Latin characters such as Chinese, Japanese, Korean, Cyrillic?

 >> See https://www.dearimgui.com/faq and https://github.com/ocornut/imgui/blob/master/docs/FONTS.md

 Q&A: Concerns

 =============

 Q: Who uses Dear ImGui?

 Q: Can you create elaborate/serious tools with Dear ImGui?

 Q: Can you reskin the look of Dear ImGui?

 Q: Why using C++ (as opposed to C)?

 >> See https://www.dearimgui.com/faq

 Q&A: Community

 ==============

 Q: How can I help?

 A: - Businesses: please reach out to "omar AT dearimgui DOT com" if you work in a place using Dear ImGui!

      We can discuss ways for your company to fund development via invoiced technical support, maintenance or sponsoring contacts.

      This is among the most useful thing you can do for Dear ImGui. With increased funding, we sustain and grow work on this project.

      >>> See https://github.com/ocornut/imgui/wiki/Funding

    - Businesses: you can also purchase licenses for the Dear ImGui Automation/Test Engine.

    - If you are experienced with Dear ImGui and C++, look at the GitHub issues, look at the Wiki, and see how you want to help and can help!

    - Disclose your usage of Dear ImGui via a dev blog post, a tweet, a screenshot, a mention somewhere etc.

      You may post screenshot or links in the gallery threads. Visuals are ideal as they inspire other programmers.

      But even without visuals, disclosing your use of dear imgui helps the library grow credibility, and help other teams and programmers with taking decisions.

    - If you have issues or if you need to hack into the library, even if you don't expect any support it is useful that you share your issues (on GitHub or privately).

*/

//-------------------------------------------------------------------------

// [SECTION] INCLUDES

//-------------------------------------------------------------------------

#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)

#define _CRT_SECURE_NO_WARNINGS

#endif

#ifndef IMGUI_DEFINE_MATH_OPERATORS

#define IMGUI_DEFINE_MATH_OPERATORS

#endif

#include "imgui.h"

#ifndef IMGUI_DISABLE

#include "imgui_internal.h"

// System includes

#include <stdio.h>      // vsnprintf, sscanf, printf

#include <stdint.h>     // intptr_t

// [Windows] On non-Visual Studio compilers, we default to IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS unless explicitly enabled

#if defined(_WIN32) && !defined(_MSC_VER) && !defined(IMGUI_ENABLE_WIN32_DEFAULT_IME_FUNCTIONS) && !defined(IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS)

#define IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS

#endif

// [Windows] OS specific includes (optional)

#if defined(_WIN32) && defined(IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS) && defined(IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS) && defined(IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS) && defined(IMGUI_DISABLE_DEFAULT_SHELL_FUNCTIONS) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS)

#define IMGUI_DISABLE_WIN32_FUNCTIONS

#endif

#if defined(_WIN32) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS)

#ifndef WIN32_LEAN_AND_MEAN

#define WIN32_LEAN_AND_MEAN

#endif

#ifndef NOMINMAX

#define NOMINMAX

#endif

#ifndef __MINGW32__

#include <Windows.h>        // _wfopen, OpenClipboard

#else

#include <windows.h>

#endif

#if defined(WINAPI_FAMILY) && (WINAPI_FAMILY == WINAPI_FAMILY_APP || WINAPI_FAMILY == WINAPI_FAMILY_GAMES)

// The UWP and GDK Win32 API subsets don't support clipboard nor IME functions

#define IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS

#define IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS

#define IMGUI_DISABLE_DEFAULT_SHELL_FUNCTIONS

#endif

#endif

// [Apple] OS specific includes

#if defined(__APPLE__)

#include <TargetConditionals.h>

#endif

// Visual Studio warnings

#ifdef _MSC_VER

#pragma warning (disable: 4127)             // condition expression is constant

#pragma warning (disable: 4996)             // 'This function or variable may be unsafe': strcpy, strdup, sprintf, vsnprintf, sscanf, fopen

#if defined(_MSC_VER) && _MSC_VER >= 1922   // MSVC 2019 16.2 or later

#pragma warning (disable: 5054)             // operator '|': deprecated between enumerations of different types

#endif

#pragma warning (disable: 26451)            // [Static Analyzer] Arithmetic overflow : Using operator 'xxx' on a 4 byte value and then casting the result to an 8 byte value. Cast the value to the wider type before calling operator 'xxx' to avoid overflow(io.2).

#pragma warning (disable: 26495)            // [Static Analyzer] Variable 'XXX' is uninitialized. Always initialize a member variable (type.6).

#pragma warning (disable: 26812)            // [Static Analyzer] The enum type 'xxx' is unscoped. Prefer 'enum class' over 'enum' (Enum.3).

#endif

// Clang/GCC warnings with -Weverything

#if defined(__clang__)

#if __has_warning("-Wunknown-warning-option")

#pragma clang diagnostic ignored "-Wunknown-warning-option"         // warning: unknown warning group 'xxx'                      // not all warnings are known by all Clang versions and they tend to be rename-happy.. so ignoring warnings triggers new warnings on some configuration. Great!

#endif

#pragma clang diagnostic ignored "-Wunknown-pragmas"                // warning: unknown warning group 'xxx'

#pragma clang diagnostic ignored "-Wold-style-cast"                 // warning: use of old-style cast                            // yes, they are more terse.

#pragma clang diagnostic ignored "-Wfloat-equal"                    // warning: comparing floating point with == or != is unsafe // storing and comparing against same constants (typically 0.0f) is ok.

#pragma clang diagnostic ignored "-Wformat-nonliteral"              // warning: format string is not a string literal            // passing non-literal to vsnformat(). yes, user passing incorrect format strings can crash the code.

#pragma clang diagnostic ignored "-Wexit-time-destructors"          // warning: declaration requires an exit-time destructor     // exit-time destruction order is undefined. if MemFree() leads to users code that has been disabled before exit it might cause problems. ImGui coding style welcomes static/globals.

#pragma clang diagnostic ignored "-Wglobal-constructors"            // warning: declaration requires a global destructor         // similar to above, not sure what the exact difference is.

#pragma clang diagnostic ignored "-Wsign-conversion"                // warning: implicit conversion changes signedness

#pragma clang diagnostic ignored "-Wformat-pedantic"                // warning: format specifies type 'void *' but the argument has type 'xxxx *' // unreasonable, would lead to casting every %p arg to void*. probably enabled by -pedantic.

#pragma clang diagnostic ignored "-Wint-to-void-pointer-cast"       // warning: cast to 'void *' from smaller integer type 'int'

#pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"  // warning: zero as null pointer constant                    // some standard header variations use #define NULL 0

#pragma clang diagnostic ignored "-Wdouble-promotion"               // warning: implicit conversion from 'float' to 'double' when passing argument to function  // using printf() is a misery with this as C++ va_arg ellipsis changes float to double.

#pragma clang diagnostic ignored "-Wimplicit-int-float-conversion"  // warning: implicit conversion from 'xxx' to 'float' may lose precision

#pragma clang diagnostic ignored "-Wunsafe-buffer-usage"            // warning: 'xxx' is an unsafe pointer used for buffer access

#elif defined(__GNUC__)

// We disable -Wpragmas because GCC doesn't provide a has_warning equivalent and some forks/patches may not follow the warning/version association.

#pragma GCC diagnostic ignored "-Wpragmas"                  // warning: unknown option after '#pragma GCC diagnostic' kind

#pragma GCC diagnostic ignored "-Wunused-function"          // warning: 'xxxx' defined but not used

#pragma GCC diagnostic ignored "-Wint-to-pointer-cast"      // warning: cast to pointer from integer of different size

#pragma GCC diagnostic ignored "-Wformat"                   // warning: format '%p' expects argument of type 'void*', but argument 6 has type 'ImGuiWindow*'

#pragma GCC diagnostic ignored "-Wdouble-promotion"         // warning: implicit conversion from 'float' to 'double' when passing argument to function

#pragma GCC diagnostic ignored "-Wconversion"               // warning: conversion to 'xxxx' from 'xxxx' may alter its value

#pragma GCC diagnostic ignored "-Wformat-nonliteral"        // warning: format not a string literal, format string not checked

#pragma GCC diagnostic ignored "-Wstrict-overflow"          // warning: assuming signed overflow does not occur when assuming that (X - c) > X is always false

#pragma GCC diagnostic ignored "-Wclass-memaccess"          // [__GNUC__ >= 8] warning: 'memset/memcpy' clearing/writing an object of type 'xxxx' with no trivial copy-assignment; use assignment or value-initialization instead

#endif

// Debug options

#define IMGUI_DEBUG_NAV_SCORING     0   // Display navigation scoring preview when hovering items. Hold CTRL to display for all candidates. CTRL+Arrow to change last direction.

#define IMGUI_DEBUG_NAV_RECTS       0   // Display the reference navigation rectangle for each window

// When using CTRL+TAB (or Gamepad Square+L/R) we delay the visual a little in order to reduce visual noise doing a fast switch.

static const float NAV_WINDOWING_HIGHLIGHT_DELAY            = 0.20f;    // Time before the highlight and screen dimming starts fading in

static const float NAV_WINDOWING_LIST_APPEAR_DELAY          = 0.15f;    // Time before the window list starts to appear

static const float NAV_ACTIVATE_HIGHLIGHT_TIMER             = 0.10f;    // Time to highlight an item activated by a shortcut.

// Window resizing from edges (when io.ConfigWindowsResizeFromEdges = true and ImGuiBackendFlags_HasMouseCursors is set in io.BackendFlags by backend)

static const float WINDOWS_HOVER_PADDING                    = 4.0f;     // Extend outside window for hovering/resizing (maxxed with TouchPadding) and inside windows for borders. Affect FindHoveredWindow().

static const float WINDOWS_RESIZE_FROM_EDGES_FEEDBACK_TIMER = 0.04f;    // Reduce visual noise by only highlighting the border after a certain time.

static const float WINDOWS_MOUSE_WHEEL_SCROLL_LOCK_TIMER    = 0.70f;    // Lock scrolled window (so it doesn't pick child windows that are scrolling through) for a certain time, unless mouse moved.

// Tooltip offset

static const ImVec2 TOOLTIP_DEFAULT_OFFSET = ImVec2(16, 10);            // Multiplied by g.Style.MouseCursorScale

// Docking

static const float DOCKING_TRANSPARENT_PAYLOAD_ALPHA        = 0.50f;    // For use with io.ConfigDockingTransparentPayload. Apply to Viewport _or_ WindowBg in host viewport.

//-------------------------------------------------------------------------

// [SECTION] FORWARD DECLARATIONS

//-------------------------------------------------------------------------

static void             SetCurrentWindow(ImGuiWindow* window);

static ImGuiWindow*     CreateNewWindow(const char* name, ImGuiWindowFlags flags);

static ImVec2           CalcNextScrollFromScrollTargetAndClamp(ImGuiWindow* window);

static void             AddWindowToSortBuffer(ImVector<ImGuiWindow*>* out_sorted_windows, ImGuiWindow* window);

// Settings